// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_MIPS

#include "src/api-arguments.h"
#include "src/code-factory.h"
#include "src/counters.h"
#include "src/debug/debug.h"
#include "src/deoptimizer.h"
#include "src/frame-constants.h"
#include "src/frames.h"
// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
#include "src/heap/heap-inl.h"
#include "src/macro-assembler-inl.h"
#include "src/mips/constants-mips.h"
#include "src/objects-inl.h"
#include "src/objects/cell.h"
#include "src/objects/foreign.h"
#include "src/objects/heap-number.h"
#include "src/objects/js-generator.h"
#include "src/objects/smi.h"
#include "src/register-configuration.h"
#include "src/runtime/runtime.h"
#include "src/wasm/wasm-objects.h"

namespace v8 {
namespace internal {

#define __ ACCESS_MASM(masm)

    void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address,
        ExitFrameType exit_frame_type)
    {
        __ li(kJavaScriptCallExtraArg1Register, ExternalReference::Create(address));
        if (exit_frame_type == BUILTIN_EXIT) {
            __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithBuiltinExitFrame),
                RelocInfo::CODE_TARGET);
        } else {
            DCHECK(exit_frame_type == EXIT);
            __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithExitFrame),
                RelocInfo::CODE_TARGET);
        }
    }

    void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0     : number of arguments
        //  -- ra     : return address
        //  -- sp[...]: constructor arguments
        // -----------------------------------
        if (FLAG_debug_code) {
            // Initial map for the builtin InternalArray functions should be maps.
            __ lw(a2, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
            __ SmiTst(a2, t0);
            __ Assert(ne, AbortReason::kUnexpectedInitialMapForInternalArrayFunction,
                t0, Operand(zero_reg));
            __ GetObjectType(a2, a3, t0);
            __ Assert(eq, AbortReason::kUnexpectedInitialMapForInternalArrayFunction,
                t0, Operand(MAP_TYPE));
        }

        // Run the native code for the InternalArray function called as a normal
        // function.
        __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
            RelocInfo::CODE_TARGET);
    }

    static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
        Runtime::FunctionId function_id)
    {
        // ----------- S t a t e -------------
        //  -- a0 : argument count (preserved for callee)
        //  -- a1 : target function (preserved for callee)
        //  -- a3 : new target (preserved for callee)
        // -----------------------------------
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            // Push a copy of the target function and the new target.
            // Push function as parameter to the runtime call.
            __ SmiTag(a0);
            __ Push(a0, a1, a3, a1);

            __ CallRuntime(function_id, 1);

            // Restore target function and new target.
            __ Pop(a0, a1, a3);
            __ SmiUntag(a0);
        }

        static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
        __ Addu(a2, v0, Code::kHeaderSize - kHeapObjectTag);
        __ Jump(a2);
    }

    namespace {

        void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm)
        {
            // ----------- S t a t e -------------
            //  -- a0     : number of arguments
            //  -- a1     : constructor function
            //  -- a3     : new target
            //  -- cp     : context
            //  -- ra     : return address
            //  -- sp[...]: constructor arguments
            // -----------------------------------

            // Enter a construct frame.
            {
                FrameScope scope(masm, StackFrame::CONSTRUCT);

                // Preserve the incoming parameters on the stack.
                __ SmiTag(a0);
                __ Push(cp, a0);
                __ SmiUntag(a0);

                // The receiver for the builtin/api call.
                __ PushRoot(RootIndex::kTheHoleValue);

                // Set up pointer to last argument.
                __ Addu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset));

                // Copy arguments and receiver to the expression stack.
                Label loop, entry;
                __ mov(t3, a0);
                // ----------- S t a t e -------------
                //  --                        a0: number of arguments (untagged)
                //  --                        a3: new target
                //  --                        t2: pointer to last argument
                //  --                        t3: counter
                //  --        sp[0*kPointerSize]: the hole (receiver)
                //  --        sp[1*kPointerSize]: number of arguments (tagged)
                //  --        sp[2*kPointerSize]: context
                // -----------------------------------
                __ jmp(&entry);
                __ bind(&loop);
                __ Lsa(t0, t2, t3, kPointerSizeLog2);
                __ lw(t1, MemOperand(t0));
                __ push(t1);
                __ bind(&entry);
                __ Addu(t3, t3, Operand(-1));
                __ Branch(&loop, greater_equal, t3, Operand(zero_reg));

                // Call the function.
                // a0: number of arguments (untagged)
                // a1: constructor function
                // a3: new target
                ParameterCount actual(a0);
                __ InvokeFunction(a1, a3, actual, CALL_FUNCTION);

                // Restore context from the frame.
                __ lw(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
                // Restore smi-tagged arguments count from the frame.
                __ lw(a1, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
                // Leave construct frame.
            }

            // Remove caller arguments from the stack and return.
            __ Lsa(sp, sp, a1, kPointerSizeLog2 - 1);
            __ Addu(sp, sp, kPointerSize);
            __ Ret();
        }

        static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
            Register scratch1, Register scratch2,
            Label* stack_overflow)
        {
            // Check the stack for overflow. We are not trying to catch
            // interruptions (e.g. debug break and preemption) here, so the "real stack
            // limit" is checked.
            __ LoadRoot(scratch1, RootIndex::kRealStackLimit);
            // Make scratch1 the space we have left. The stack might already be overflowed
            // here which will cause scratch1 to become negative.
            __ subu(scratch1, sp, scratch1);
            // Check if the arguments will overflow the stack.
            __ sll(scratch2, num_args, kPointerSizeLog2);
            // Signed comparison.
            __ Branch(stack_overflow, le, scratch1, Operand(scratch2));
        }

    } // namespace

    // The construct stub for ES5 constructor functions and ES6 class constructors.
    void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  --      a0: number of arguments (untagged)
        //  --      a1: constructor function
        //  --      a3: new target
        //  --      cp: context
        //  --      ra: return address
        //  -- sp[...]: constructor arguments
        // -----------------------------------

        // Enter a construct frame.
        {
            FrameScope scope(masm, StackFrame::CONSTRUCT);
            Label post_instantiation_deopt_entry, not_create_implicit_receiver;

            // Preserve the incoming parameters on the stack.
            __ SmiTag(a0);
            __ Push(cp, a0, a1);
            __ PushRoot(RootIndex::kTheHoleValue);
            __ Push(a3);

            // ----------- S t a t e -------------
            //  --        sp[0*kPointerSize]: new target
            //  --        sp[1*kPointerSize]: padding
            //  -- a1 and sp[2*kPointerSize]: constructor function
            //  --        sp[3*kPointerSize]: number of arguments (tagged)
            //  --        sp[4*kPointerSize]: context
            // -----------------------------------

            __ lw(t2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
            __ lw(t2, FieldMemOperand(t2, SharedFunctionInfo::kFlagsOffset));
            __ DecodeField<SharedFunctionInfo::FunctionKindBits>(t2);
            __ JumpIfIsInRange(t2, kDefaultDerivedConstructor, kDerivedConstructor,
                &not_create_implicit_receiver);

            // If not derived class constructor: Allocate the new receiver object.
            __ IncrementCounter(masm->isolate()->counters()->constructed_objects(), 1,
                t2, t3);
            __ Call(BUILTIN_CODE(masm->isolate(), FastNewObject),
                RelocInfo::CODE_TARGET);
            __ Branch(&post_instantiation_deopt_entry);

            // Else: use TheHoleValue as receiver for constructor call
            __ bind(&not_create_implicit_receiver);
            __ LoadRoot(v0, RootIndex::kTheHoleValue);

            // ----------- S t a t e -------------
            //  --                          v0: receiver
            //  -- Slot 4 / sp[0*kPointerSize]: new target
            //  -- Slot 3 / sp[1*kPointerSize]: padding
            //  -- Slot 2 / sp[2*kPointerSize]: constructor function
            //  -- Slot 1 / sp[3*kPointerSize]: number of arguments (tagged)
            //  -- Slot 0 / sp[4*kPointerSize]: context
            // -----------------------------------
            // Deoptimizer enters here.
            masm->isolate()->heap()->SetConstructStubCreateDeoptPCOffset(
                masm->pc_offset());
            __ bind(&post_instantiation_deopt_entry);

            // Restore new target.
            __ Pop(a3);
            // Push the allocated receiver to the stack. We need two copies
            // because we may have to return the original one and the calling
            // conventions dictate that the called function pops the receiver.
            __ Push(v0, v0);

            // ----------- S t a t e -------------
            //  --                 r3: new target
            //  -- sp[0*kPointerSize]: implicit receiver
            //  -- sp[1*kPointerSize]: implicit receiver
            //  -- sp[2*kPointerSize]: padding
            //  -- sp[3*kPointerSize]: constructor function
            //  -- sp[4*kPointerSize]: number of arguments (tagged)
            //  -- sp[5*kPointerSize]: context
            // -----------------------------------

            // Restore constructor function and argument count.
            __ lw(a1, MemOperand(fp, ConstructFrameConstants::kConstructorOffset));
            __ lw(a0, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
            __ SmiUntag(a0);

            // Set up pointer to last argument.
            __ Addu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset));

            Label enough_stack_space, stack_overflow;
            Generate_StackOverflowCheck(masm, a0, t0, t1, &stack_overflow);
            __ Branch(&enough_stack_space);

            __ bind(&stack_overflow);
            // Restore the context from the frame.
            __ lw(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
            __ CallRuntime(Runtime::kThrowStackOverflow);
            // Unreachable code.
            __ break_(0xCC);

            __ bind(&enough_stack_space);

            // Copy arguments and receiver to the expression stack.
            Label loop, entry;
            __ mov(t3, a0);
            // ----------- S t a t e -------------
            //  --                        a0: number of arguments (untagged)
            //  --                        a3: new target
            //  --                        t2: pointer to last argument
            //  --                        t3: counter
            //  --        sp[0*kPointerSize]: implicit receiver
            //  --        sp[1*kPointerSize]: implicit receiver
            //  --        sp[2*kPointerSize]: padding
            //  -- a1 and sp[3*kPointerSize]: constructor function
            //  --        sp[4*kPointerSize]: number of arguments (tagged)
            //  --        sp[5*kPointerSize]: context
            // -----------------------------------
            __ jmp(&entry);
            __ bind(&loop);
            __ Lsa(t0, t2, t3, kPointerSizeLog2);
            __ lw(t1, MemOperand(t0));
            __ push(t1);
            __ bind(&entry);
            __ Addu(t3, t3, Operand(-1));
            __ Branch(&loop, greater_equal, t3, Operand(zero_reg));

            // Call the function.
            ParameterCount actual(a0);
            __ InvokeFunction(a1, a3, actual, CALL_FUNCTION);

            // ----------- S t a t e -------------
            //  --                 v0: constructor result
            //  -- sp[0*kPointerSize]: implicit receiver
            //  -- sp[1*kPointerSize]: padding
            //  -- sp[2*kPointerSize]: constructor function
            //  -- sp[3*kPointerSize]: number of arguments
            //  -- sp[4*kPointerSize]: context
            // -----------------------------------

            // Store offset of return address for deoptimizer.
            masm->isolate()->heap()->SetConstructStubInvokeDeoptPCOffset(
                masm->pc_offset());

            // Restore the context from the frame.
            __ lw(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));

            // If the result is an object (in the ECMA sense), we should get rid
            // of the receiver and use the result; see ECMA-262 section 13.2.2-7
            // on page 74.
            Label use_receiver, do_throw, leave_frame;

            // If the result is undefined, we jump out to using the implicit receiver.
            __ JumpIfRoot(v0, RootIndex::kUndefinedValue, &use_receiver);

            // Otherwise we do a smi check and fall through to check if the return value
            // is a valid receiver.

            // If the result is a smi, it is *not* an object in the ECMA sense.
            __ JumpIfSmi(v0, &use_receiver);

            // If the type of the result (stored in its map) is less than
            // FIRST_JS_RECEIVER_TYPE, it is not an object in the ECMA sense.
            __ GetObjectType(v0, t2, t2);
            STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
            __ Branch(&leave_frame, greater_equal, t2, Operand(FIRST_JS_RECEIVER_TYPE));
            __ Branch(&use_receiver);

            __ bind(&do_throw);
            __ CallRuntime(Runtime::kThrowConstructorReturnedNonObject);

            // Throw away the result of the constructor invocation and use the
            // on-stack receiver as the result.
            __ bind(&use_receiver);
            __ lw(v0, MemOperand(sp, 0 * kPointerSize));
            __ JumpIfRoot(v0, RootIndex::kTheHoleValue, &do_throw);

            __ bind(&leave_frame);
            // Restore smi-tagged arguments count from the frame.
            __ lw(a1, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
            // Leave construct frame.
        }
        // Remove caller arguments from the stack and return.
        __ Lsa(sp, sp, a1, kPointerSizeLog2 - kSmiTagSize);
        __ Addu(sp, sp, kPointerSize);
        __ Ret();
    }

    void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm)
    {
        Generate_JSBuiltinsConstructStubHelper(masm);
    }

    void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm)
    {
        FrameScope scope(masm, StackFrame::INTERNAL);
        __ Push(a1);
        __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
    }

    // Clobbers scratch1 and scratch2; preserves all other registers.
    static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
        Register scratch1, Register scratch2)
    {
        // Check the stack for overflow. We are not trying to catch
        // interruptions (e.g. debug break and preemption) here, so the "real stack
        // limit" is checked.
        Label okay;
        __ LoadRoot(scratch1, RootIndex::kRealStackLimit);
        // Make a2 the space we have left. The stack might already be overflowed
        // here which will cause a2 to become negative.
        __ Subu(scratch1, sp, scratch1);
        // Check if the arguments will overflow the stack.
        __ sll(scratch2, argc, kPointerSizeLog2);
        // Signed comparison.
        __ Branch(&okay, gt, scratch1, Operand(scratch2));

        // Out of stack space.
        __ CallRuntime(Runtime::kThrowStackOverflow);

        __ bind(&okay);
    }

    namespace {

        // Used by JSEntryTrampoline to refer C++ parameter to JSEntryVariant.
        constexpr int kPushedStackSpace = kCArgsSlotsSize + (kNumCalleeSaved + 1) * kPointerSize + kNumCalleeSavedFPU * kDoubleSize + 4 * kPointerSize + EntryFrameConstants::kCallerFPOffset;

        // Called with the native C calling convention. The corresponding function
        // signature is either:
        //
        //   using JSEntryFunction = GeneratedCode<Address(
        //       Address root_register_value, Address new_target, Address target,
        //       Address receiver, intptr_t argc, Address** argv)>;
        // or
        //   using JSEntryFunction = GeneratedCode<Address(
        //       Address root_register_value, MicrotaskQueue* microtask_queue)>;
        //
        // Passes through a0, a1, a2, a3 and stack to JSEntryTrampoline.
        void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
            Builtins::Name entry_trampoline)
        {
            Label invoke, handler_entry, exit;

            int pushed_stack_space = kCArgsSlotsSize;
            {
                NoRootArrayScope no_root_array(masm);

                // Registers:
                // a0: root_register_value

                // Save callee saved registers on the stack.
                __ MultiPush(kCalleeSaved | ra.bit());
                pushed_stack_space += kNumCalleeSaved * kPointerSize + kPointerSize /* ra */;

                // Save callee-saved FPU registers.
                __ MultiPushFPU(kCalleeSavedFPU);
                pushed_stack_space += kNumCalleeSavedFPU * kDoubleSize;

                // Set up the reserved register for 0.0.
                __ Move(kDoubleRegZero, 0.0);

                // Initialize the root register.
                // C calling convention. The first argument is passed in a0.
                __ mov(kRootRegister, a0);
            }

            // We build an EntryFrame.
            __ li(t3, Operand(-1)); // Push a bad frame pointer to fail if it is used.
            __ li(t2, Operand(StackFrame::TypeToMarker(type)));
            __ li(t1, Operand(StackFrame::TypeToMarker(type)));
            __ li(t0, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, masm->isolate()));
            __ lw(t0, MemOperand(t0));
            __ Push(t3, t2, t1, t0);
            pushed_stack_space += 4 * kPointerSize;

            // Set up frame pointer for the frame to be pushed.
            __ addiu(fp, sp, -EntryFrameConstants::kCallerFPOffset);
            pushed_stack_space += EntryFrameConstants::kCallerFPOffset;

            // Registers:
            // a0: root_register_value
            //
            // Stack:
            // caller fp          |
            // function slot      | entry frame
            // context slot       |
            // bad fp (0xFF...F)  |
            // callee saved registers + ra
            // 4 args slots

            // If this is the outermost JS call, set js_entry_sp value.
            Label non_outermost_js;
            ExternalReference js_entry_sp = ExternalReference::Create(
                IsolateAddressId::kJSEntrySPAddress, masm->isolate());
            __ li(t1, js_entry_sp);
            __ lw(t2, MemOperand(t1));
            __ Branch(&non_outermost_js, ne, t2, Operand(zero_reg));
            __ sw(fp, MemOperand(t1));
            __ li(t0, Operand(StackFrame::OUTERMOST_JSENTRY_FRAME));
            Label cont;
            __ b(&cont);
            __ nop(); // Branch delay slot nop.
            __ bind(&non_outermost_js);
            __ li(t0, Operand(StackFrame::INNER_JSENTRY_FRAME));
            __ bind(&cont);
            __ push(t0);

            // Jump to a faked try block that does the invoke, with a faked catch
            // block that sets the pending exception.
            __ jmp(&invoke);
            __ bind(&handler_entry);

            // Store the current pc as the handler offset. It's used later to create the
            // handler table.
            masm->isolate()->builtins()->SetJSEntryHandlerOffset(handler_entry.pos());

            // Caught exception: Store result (exception) in the pending exception
            // field in the JSEnv and return a failure sentinel.  Coming in here the
            // fp will be invalid because the PushStackHandler below sets it to 0 to
            // signal the existence of the JSEntry frame.
            __ li(t0, ExternalReference::Create(IsolateAddressId::kPendingExceptionAddress, masm->isolate()));
            __ sw(v0, MemOperand(t0)); // We come back from 'invoke'. result is in v0.
            __ LoadRoot(v0, RootIndex::kException);
            __ b(&exit); // b exposes branch delay slot.
            __ nop(); // Branch delay slot nop.

            // Invoke: Link this frame into the handler chain.
            __ bind(&invoke);
            __ PushStackHandler();
            // If an exception not caught by another handler occurs, this handler
            // returns control to the code after the bal(&invoke) above, which
            // restores all kCalleeSaved registers (including cp and fp) to their
            // saved values before returning a failure to C.
            //
            // Preserve a1, a2 and a3 passed by C++ and pass them to the trampoline.
            //
            // Stack:
            // handler frame
            // entry frame
            // callee saved registers + ra
            // 4 args slots
            //
            // Invoke the function by calling through JS entry trampoline builtin and
            // pop the faked function when we return.
            Handle<Code> trampoline_code = masm->isolate()->builtins()->builtin_handle(entry_trampoline);
            DCHECK_EQ(kPushedStackSpace, pushed_stack_space);
            __ Call(trampoline_code, RelocInfo::CODE_TARGET);

            // Unlink this frame from the handler chain.
            __ PopStackHandler();

            __ bind(&exit); // v0 holds result
            // Check if the current stack frame is marked as the outermost JS frame.
            Label non_outermost_js_2;
            __ pop(t1);
            __ Branch(&non_outermost_js_2, ne, t1,
                Operand(StackFrame::OUTERMOST_JSENTRY_FRAME));
            __ li(t1, ExternalReference(js_entry_sp));
            __ sw(zero_reg, MemOperand(t1));
            __ bind(&non_outermost_js_2);

            // Restore the top frame descriptors from the stack.
            __ pop(t1);
            __ li(t0, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, masm->isolate()));
            __ sw(t1, MemOperand(t0));

            // Reset the stack to the callee saved registers.
            __ addiu(sp, sp, -EntryFrameConstants::kCallerFPOffset);

            // Restore callee-saved fpu registers.
            __ MultiPopFPU(kCalleeSavedFPU);

            // Restore callee saved registers from the stack.
            __ MultiPop(kCalleeSaved | ra.bit());
            // Return.
            __ Jump(ra);
        }

    } // namespace

    void Builtins::Generate_JSEntry(MacroAssembler* masm)
    {
        Generate_JSEntryVariant(masm, StackFrame::ENTRY,
            Builtins::kJSEntryTrampoline);
    }

    void Builtins::Generate_JSConstructEntry(MacroAssembler* masm)
    {
        Generate_JSEntryVariant(masm, StackFrame::CONSTRUCT_ENTRY,
            Builtins::kJSConstructEntryTrampoline);
    }

    void Builtins::Generate_JSRunMicrotasksEntry(MacroAssembler* masm)
    {
        Generate_JSEntryVariant(masm, StackFrame::ENTRY,
            Builtins::kRunMicrotasksTrampoline);
    }

    static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
        bool is_construct)
    {
        // ----------- S t a t e -------------
        //  -- a0: root_register_value (unused)
        //  -- a1: new.target
        //  -- a2: function
        //  -- a3: receiver_pointer
        //  -- [fp + kPushedStackSpace + 0 * kPointerSize]: argc
        //  -- [fp + kPushedStackSpace + 1 * kPointerSize]: argv
        // -----------------------------------

        // Enter an internal frame.
        {
            FrameScope scope(masm, StackFrame::INTERNAL);

            // Setup the context (we need to use the caller context from the isolate).
            ExternalReference context_address = ExternalReference::Create(
                IsolateAddressId::kContextAddress, masm->isolate());
            __ li(cp, context_address);
            __ lw(cp, MemOperand(cp));

            // Push the function and the receiver onto the stack.
            __ Push(a2, a3);

            __ mov(a3, a1);
            __ mov(a1, a2);

            __ lw(s0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
            __ lw(a0,
                MemOperand(s0, kPushedStackSpace + EntryFrameConstants::kArgcOffset));
            __ lw(s0,
                MemOperand(s0, kPushedStackSpace + EntryFrameConstants::kArgvOffset));

            // a0: argc
            // a1: function
            // a3: new.target
            // s0: argv

            // Check if we have enough stack space to push all arguments.
            // Clobbers a2 and t0.
            Generate_CheckStackOverflow(masm, a0, a2, t0);

            // Copy arguments to the stack in a loop.
            // a0: argc
            // s0: argv, i.e. points to first arg
            Label loop, entry;
            __ Lsa(t2, s0, a0, kPointerSizeLog2);
            __ b(&entry);
            __ nop(); // Branch delay slot nop.
            // t2 points past last arg.
            __ bind(&loop);
            __ lw(t0, MemOperand(s0)); // Read next parameter.
            __ addiu(s0, s0, kPointerSize);
            __ lw(t0, MemOperand(t0)); // Dereference handle.
            __ push(t0); // Push parameter.
            __ bind(&entry);
            __ Branch(&loop, ne, s0, Operand(t2));

            // a0: argc
            // a1: function
            // a3: new.target

            // Initialize all JavaScript callee-saved registers, since they will be seen
            // by the garbage collector as part of handlers.
            __ LoadRoot(t0, RootIndex::kUndefinedValue);
            __ mov(s0, t0);
            __ mov(s1, t0);
            __ mov(s2, t0);
            __ mov(s3, t0);
            __ mov(s4, t0);
            __ mov(s5, t0);
            // s6 holds the root address. Do not clobber.
            // s7 is cp. Do not init.

            // Invoke the code.
            Handle<Code> builtin = is_construct
                ? BUILTIN_CODE(masm->isolate(), Construct)
                : masm->isolate()->builtins()->Call();
            __ Call(builtin, RelocInfo::CODE_TARGET);

            // Leave internal frame.
        }

        __ Jump(ra);
    }

    void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm)
    {
        Generate_JSEntryTrampolineHelper(masm, false);
    }

    void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm)
    {
        Generate_JSEntryTrampolineHelper(masm, true);
    }

    void Builtins::Generate_RunMicrotasksTrampoline(MacroAssembler* masm)
    {
        // a1: microtask_queue
        __ mov(RunMicrotasksDescriptor::MicrotaskQueueRegister(), a1);
        __ Jump(BUILTIN_CODE(masm->isolate(), RunMicrotasks), RelocInfo::CODE_TARGET);
    }

    static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
        Register sfi_data,
        Register scratch1)
    {
        Label done;

        __ GetObjectType(sfi_data, scratch1, scratch1);
        __ Branch(&done, ne, scratch1, Operand(INTERPRETER_DATA_TYPE));
        __ lw(sfi_data,
            FieldMemOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));

        __ bind(&done);
    }

    // static
    void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- v0 : the value to pass to the generator
        //  -- a1 : the JSGeneratorObject to resume
        //  -- ra : return address
        // -----------------------------------

        __ AssertGeneratorObject(a1);

        // Store input value into generator object.
        __ sw(v0, FieldMemOperand(a1, JSGeneratorObject::kInputOrDebugPosOffset));
        __ RecordWriteField(a1, JSGeneratorObject::kInputOrDebugPosOffset, v0, a3,
            kRAHasNotBeenSaved, kDontSaveFPRegs);

        // Load suspended function and context.
        __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
        __ lw(cp, FieldMemOperand(t0, JSFunction::kContextOffset));

        // Flood function if we are stepping.
        Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
        Label stepping_prepared;
        ExternalReference debug_hook = ExternalReference::debug_hook_on_function_call_address(masm->isolate());
        __ li(t1, debug_hook);
        __ lb(t1, MemOperand(t1));
        __ Branch(&prepare_step_in_if_stepping, ne, t1, Operand(zero_reg));

        // Flood function if we need to continue stepping in the suspended generator.
        ExternalReference debug_suspended_generator = ExternalReference::debug_suspended_generator_address(masm->isolate());
        __ li(t1, debug_suspended_generator);
        __ lw(t1, MemOperand(t1));
        __ Branch(&prepare_step_in_suspended_generator, eq, a1, Operand(t1));
        __ bind(&stepping_prepared);

        // Check the stack for overflow. We are not trying to catch interruptions
        // (i.e. debug break and preemption) here, so check the "real stack limit".
        Label stack_overflow;
        __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
        __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));

        // Push receiver.
        __ lw(t1, FieldMemOperand(a1, JSGeneratorObject::kReceiverOffset));
        __ Push(t1);

        // ----------- S t a t e -------------
        //  -- a1    : the JSGeneratorObject to resume
        //  -- t0    : generator function
        //  -- cp    : generator context
        //  -- ra    : return address
        //  -- sp[0] : generator receiver
        // -----------------------------------

        // Copy the function arguments from the generator object's register file.

        __ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
        __ lhu(a3,
            FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
        __ lw(t1,
            FieldMemOperand(a1, JSGeneratorObject::kParametersAndRegistersOffset));
        {
            Label done_loop, loop;
            __ Move(t2, zero_reg);
            __ bind(&loop);
            __ Subu(a3, a3, Operand(1));
            __ Branch(&done_loop, lt, a3, Operand(zero_reg));
            __ Lsa(kScratchReg, t1, t2, kPointerSizeLog2);
            __ lw(kScratchReg, FieldMemOperand(kScratchReg, FixedArray::kHeaderSize));
            __ Push(kScratchReg);
            __ Addu(t2, t2, Operand(1));
            __ Branch(&loop);
            __ bind(&done_loop);
        }

        // Underlying function needs to have bytecode available.
        if (FLAG_debug_code) {
            __ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
            __ lw(a3, FieldMemOperand(a3, SharedFunctionInfo::kFunctionDataOffset));
            GetSharedFunctionInfoBytecode(masm, a3, a0);
            __ GetObjectType(a3, a3, a3);
            __ Assert(eq, AbortReason::kMissingBytecodeArray, a3,
                Operand(BYTECODE_ARRAY_TYPE));
        }

        // Resume (Ignition/TurboFan) generator object.
        {
            __ lw(a0, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
            __ lhu(a0, FieldMemOperand(a0, SharedFunctionInfo::kFormalParameterCountOffset));
            // We abuse new.target both to indicate that this is a resume call and to
            // pass in the generator object.  In ordinary calls, new.target is always
            // undefined because generator functions are non-constructable.
            __ Move(a3, a1);
            __ Move(a1, t0);
            static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
            __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
            __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
            __ Jump(a2);
        }

        __ bind(&prepare_step_in_if_stepping);
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            __ Push(a1, t0);
            // Push hole as receiver since we do not use it for stepping.
            __ PushRoot(RootIndex::kTheHoleValue);
            __ CallRuntime(Runtime::kDebugOnFunctionCall);
            __ Pop(a1);
        }
        __ Branch(USE_DELAY_SLOT, &stepping_prepared);
        __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));

        __ bind(&prepare_step_in_suspended_generator);
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            __ Push(a1);
            __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
            __ Pop(a1);
        }
        __ Branch(USE_DELAY_SLOT, &stepping_prepared);
        __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));

        __ bind(&stack_overflow);
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            __ CallRuntime(Runtime::kThrowStackOverflow);
            __ break_(0xCC); // This should be unreachable.
        }
    }

    static void ReplaceClosureCodeWithOptimizedCode(
        MacroAssembler* masm, Register optimized_code, Register closure,
        Register scratch1, Register scratch2, Register scratch3)
    {
        // Store code entry in the closure.
        __ sw(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
        __ mov(scratch1, optimized_code); // Write barrier clobbers scratch1 below.
        __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
            kRAHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
            OMIT_SMI_CHECK);
    }

    static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch)
    {
        Register args_count = scratch;

        // Get the arguments + receiver count.
        __ lw(args_count,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
        __ lw(args_count,
            FieldMemOperand(args_count, BytecodeArray::kParameterSizeOffset));

        // Leave the frame (also dropping the register file).
        __ LeaveFrame(StackFrame::INTERPRETED);

        // Drop receiver + arguments.
        __ Addu(sp, sp, args_count);
    }

    // Tail-call |function_id| if |smi_entry| == |marker|
    static void TailCallRuntimeIfMarkerEquals(MacroAssembler* masm,
        Register smi_entry,
        OptimizationMarker marker,
        Runtime::FunctionId function_id)
    {
        Label no_match;
        __ Branch(&no_match, ne, smi_entry, Operand(Smi::FromEnum(marker)));
        GenerateTailCallToReturnedCode(masm, function_id);
        __ bind(&no_match);
    }

    static void MaybeTailCallOptimizedCodeSlot(MacroAssembler* masm,
        Register feedback_vector,
        Register scratch1, Register scratch2,
        Register scratch3)
    {
        // ----------- S t a t e -------------
        //  -- a0 : argument count (preserved for callee if needed, and caller)
        //  -- a3 : new target (preserved for callee if needed, and caller)
        //  -- a1 : target function (preserved for callee if needed, and caller)
        //  -- feedback vector (preserved for caller if needed)
        // -----------------------------------
        DCHECK(
            !AreAliased(feedback_vector, a0, a1, a3, scratch1, scratch2, scratch3));

        Label optimized_code_slot_is_weak_ref, fallthrough;

        Register closure = a1;
        Register optimized_code_entry = scratch1;

        __ lw(optimized_code_entry,
            FieldMemOperand(feedback_vector, FeedbackVector::kOptimizedCodeOffset));

        // Check if the code entry is a Smi. If yes, we interpret it as an
        // optimisation marker. Otherwise, interpret it as a weak cell to a code
        // object.
        __ JumpIfNotSmi(optimized_code_entry, &optimized_code_slot_is_weak_ref);

        {
            // Optimized code slot is a Smi optimization marker.

            // Fall through if no optimization trigger.
            __ Branch(&fallthrough, eq, optimized_code_entry,
                Operand(Smi::FromEnum(OptimizationMarker::kNone)));

            TailCallRuntimeIfMarkerEquals(masm, optimized_code_entry,
                OptimizationMarker::kLogFirstExecution,
                Runtime::kFunctionFirstExecution);
            TailCallRuntimeIfMarkerEquals(masm, optimized_code_entry,
                OptimizationMarker::kCompileOptimized,
                Runtime::kCompileOptimized_NotConcurrent);
            TailCallRuntimeIfMarkerEquals(
                masm, optimized_code_entry,
                OptimizationMarker::kCompileOptimizedConcurrent,
                Runtime::kCompileOptimized_Concurrent);

            {
                // Otherwise, the marker is InOptimizationQueue, so fall through hoping
                // that an interrupt will eventually update the slot with optimized code.
                if (FLAG_debug_code) {
                    __ Assert(
                        eq, AbortReason::kExpectedOptimizationSentinel,
                        optimized_code_entry,
                        Operand(Smi::FromEnum(OptimizationMarker::kInOptimizationQueue)));
                }
                __ jmp(&fallthrough);
            }
        }

        {
            // Optimized code slot is a weak reference.
            __ bind(&optimized_code_slot_is_weak_ref);

            __ LoadWeakValue(optimized_code_entry, optimized_code_entry, &fallthrough);

            // Check if the optimized code is marked for deopt. If it is, call the
            // runtime to clear it.
            Label found_deoptimized_code;
            __ lw(scratch2, FieldMemOperand(optimized_code_entry, Code::kCodeDataContainerOffset));
            __ lw(scratch2, FieldMemOperand(scratch2, CodeDataContainer::kKindSpecificFlagsOffset));
            __ And(scratch2, scratch2, Operand(1 << Code::kMarkedForDeoptimizationBit));
            __ Branch(&found_deoptimized_code, ne, scratch2, Operand(zero_reg));

            // Optimized code is good, get it into the closure and link the closure into
            // the optimized functions list, then tail call the optimized code.
            // The feedback vector is no longer used, so re-use it as a scratch
            // register.
            ReplaceClosureCodeWithOptimizedCode(masm, optimized_code_entry, closure,
                scratch2, scratch3, feedback_vector);
            static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
            __ Addu(a2, optimized_code_entry, Code::kHeaderSize - kHeapObjectTag);
            __ Jump(a2);

            // Optimized code slot contains deoptimized code, evict it and re-enter the
            // losure's code.
            __ bind(&found_deoptimized_code);
            GenerateTailCallToReturnedCode(masm, Runtime::kEvictOptimizedCodeSlot);
        }

        // Fall-through if the optimized code cell is clear and there is no
        // optimization marker.
        __ bind(&fallthrough);
    }

    // Advance the current bytecode offset. This simulates what all bytecode
    // handlers do upon completion of the underlying operation. Will bail out to a
    // label if the bytecode (without prefix) is a return bytecode.
    static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
        Register bytecode_array,
        Register bytecode_offset,
        Register bytecode, Register scratch1,
        Register scratch2, Label* if_return)
    {
        Register bytecode_size_table = scratch1;
        DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
            bytecode));

        __ li(bytecode_size_table, ExternalReference::bytecode_size_table_address());

        // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
        Label process_bytecode, extra_wide;
        STATIC_ASSERT(0 == static_cast<int>(interpreter::Bytecode::kWide));
        STATIC_ASSERT(1 == static_cast<int>(interpreter::Bytecode::kExtraWide));
        STATIC_ASSERT(2 == static_cast<int>(interpreter::Bytecode::kDebugBreakWide));
        STATIC_ASSERT(3 == static_cast<int>(interpreter::Bytecode::kDebugBreakExtraWide));
        __ Branch(&process_bytecode, hi, bytecode, Operand(3));
        __ And(scratch2, bytecode, Operand(1));
        __ Branch(&extra_wide, ne, scratch2, Operand(zero_reg));

        // Load the next bytecode and update table to the wide scaled table.
        __ Addu(bytecode_offset, bytecode_offset, Operand(1));
        __ Addu(scratch2, bytecode_array, bytecode_offset);
        __ lbu(bytecode, MemOperand(scratch2));
        __ Addu(bytecode_size_table, bytecode_size_table,
            Operand(kIntSize * interpreter::Bytecodes::kBytecodeCount));
        __ jmp(&process_bytecode);

        __ bind(&extra_wide);
        // Load the next bytecode and update table to the extra wide scaled table.
        __ Addu(bytecode_offset, bytecode_offset, Operand(1));
        __ Addu(scratch2, bytecode_array, bytecode_offset);
        __ lbu(bytecode, MemOperand(scratch2));
        __ Addu(bytecode_size_table, bytecode_size_table,
            Operand(2 * kIntSize * interpreter::Bytecodes::kBytecodeCount));

        __ bind(&process_bytecode);

// Bailout to the return label if this is a return bytecode.
#define JUMP_IF_EQUAL(NAME)            \
    __ Branch(if_return, eq, bytecode, \
        Operand(static_cast<int>(interpreter::Bytecode::k##NAME)));
        RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
#undef JUMP_IF_EQUAL

        // Otherwise, load the size of the current bytecode and advance the offset.
        __ Lsa(scratch2, bytecode_size_table, bytecode, 2);
        __ lw(scratch2, MemOperand(scratch2));
        __ Addu(bytecode_offset, bytecode_offset, scratch2);
    }

    // Generate code for entering a JS function with the interpreter.
    // On entry to the function the receiver and arguments have been pushed on the
    // stack left to right.  The actual argument count matches the formal parameter
    // count expected by the function.
    //
    // The live registers are:
    //   o a1: the JS function object being called.
    //   o a3: the incoming new target or generator object
    //   o cp: our context
    //   o fp: the caller's frame pointer
    //   o sp: stack pointer
    //   o ra: return address
    //
    // The function builds an interpreter frame.  See InterpreterFrameConstants in
    // frames.h for its layout.
    void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm)
    {
        Register closure = a1;
        Register feedback_vector = a2;

        // Get the bytecode array from the function object and load it into
        // kInterpreterBytecodeArrayRegister.
        __ lw(a0, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
        __ lw(kInterpreterBytecodeArrayRegister,
            FieldMemOperand(a0, SharedFunctionInfo::kFunctionDataOffset));
        GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister, t0);

        // The bytecode array could have been flushed from the shared function info,
        // if so, call into CompileLazy.
        Label compile_lazy;
        __ GetObjectType(kInterpreterBytecodeArrayRegister, a0, a0);
        __ Branch(&compile_lazy, ne, a0, Operand(BYTECODE_ARRAY_TYPE));

        // Load the feedback vector from the closure.
        __ lw(feedback_vector,
            FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
        __ lw(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
        // Read off the optimized code slot in the feedback vector, and if there
        // is optimized code or an optimization marker, call that instead.
        MaybeTailCallOptimizedCodeSlot(masm, feedback_vector, t0, t3, t1);

        // Open a frame scope to indicate that there is a frame on the stack.  The
        // MANUAL indicates that the scope shouldn't actually generate code to set up
        // the frame (that is done below).
        FrameScope frame_scope(masm, StackFrame::MANUAL);
        __ PushStandardFrame(closure);

        // Increment invocation count for the function.
        __ lw(t0, FieldMemOperand(feedback_vector, FeedbackVector::kInvocationCountOffset));
        __ Addu(t0, t0, Operand(1));
        __ sw(t0, FieldMemOperand(feedback_vector, FeedbackVector::kInvocationCountOffset));

        // Reset code age.
        DCHECK_EQ(0, BytecodeArray::kNoAgeBytecodeAge);
        __ sb(zero_reg, FieldMemOperand(kInterpreterBytecodeArrayRegister, BytecodeArray::kBytecodeAgeOffset));

        // Load initial bytecode offset.
        __ li(kInterpreterBytecodeOffsetRegister,
            Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));

        // Push bytecode array and Smi tagged bytecode array offset.
        __ SmiTag(t0, kInterpreterBytecodeOffsetRegister);
        __ Push(kInterpreterBytecodeArrayRegister, t0);

        // Allocate the local and temporary register file on the stack.
        {
            // Load frame size from the BytecodeArray object.
            __ lw(t0, FieldMemOperand(kInterpreterBytecodeArrayRegister, BytecodeArray::kFrameSizeOffset));

            // Do a stack check to ensure we don't go over the limit.
            Label ok;
            __ Subu(t1, sp, Operand(t0));
            __ LoadRoot(a2, RootIndex::kRealStackLimit);
            __ Branch(&ok, hs, t1, Operand(a2));
            __ CallRuntime(Runtime::kThrowStackOverflow);
            __ bind(&ok);

            // If ok, push undefined as the initial value for all register file entries.
            Label loop_header;
            Label loop_check;
            __ LoadRoot(t1, RootIndex::kUndefinedValue);
            __ Branch(&loop_check);
            __ bind(&loop_header);
            // TODO(rmcilroy): Consider doing more than one push per loop iteration.
            __ push(t1);
            // Continue loop if not done.
            __ bind(&loop_check);
            __ Subu(t0, t0, Operand(kPointerSize));
            __ Branch(&loop_header, ge, t0, Operand(zero_reg));
        }

        // If the bytecode array has a valid incoming new target or generator object
        // register, initialize it with incoming value which was passed in r3.
        Label no_incoming_new_target_or_generator_register;
        __ lw(t1, FieldMemOperand(kInterpreterBytecodeArrayRegister, BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
        __ Branch(&no_incoming_new_target_or_generator_register, eq, t1,
            Operand(zero_reg));
        __ Lsa(t1, fp, t1, kPointerSizeLog2);
        __ sw(a3, MemOperand(t1));
        __ bind(&no_incoming_new_target_or_generator_register);

        // Load accumulator with undefined.
        __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);

        // Load the dispatch table into a register and dispatch to the bytecode
        // handler at the current bytecode offset.
        Label do_dispatch;
        __ bind(&do_dispatch);
        __ li(kInterpreterDispatchTableRegister,
            ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
        __ Addu(a0, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
        __ lbu(t3, MemOperand(a0));
        __ Lsa(kScratchReg, kInterpreterDispatchTableRegister, t3, kPointerSizeLog2);
        __ lw(kJavaScriptCallCodeStartRegister, MemOperand(kScratchReg));
        __ Call(kJavaScriptCallCodeStartRegister);
        masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());

        // Any returns to the entry trampoline are either due to the return bytecode
        // or the interpreter tail calling a builtin and then a dispatch.

        // Get bytecode array and bytecode offset from the stack frame.
        __ lw(kInterpreterBytecodeArrayRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
        __ lw(kInterpreterBytecodeOffsetRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
        __ SmiUntag(kInterpreterBytecodeOffsetRegister);
        // Either return, or advance to the next bytecode and dispatch.
        Label do_return;
        __ Addu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
        __ lbu(a1, MemOperand(a1));
        AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister, a1, a2, a3,
            &do_return);
        __ jmp(&do_dispatch);

        __ bind(&do_return);
        // The return value is in v0.
        LeaveInterpreterFrame(masm, t0);
        __ Jump(ra);

        __ bind(&compile_lazy);
        GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
        // Unreachable code.
        __ break_(0xCC);
    }

    static void Generate_InterpreterPushArgs(MacroAssembler* masm,
        Register num_args, Register index,
        Register scratch, Register scratch2)
    {
        // Find the address of the last argument.
        __ mov(scratch2, num_args);
        __ sll(scratch2, scratch2, kPointerSizeLog2);
        __ Subu(scratch2, index, Operand(scratch2));

        // Push the arguments.
        Label loop_header, loop_check;
        __ Branch(&loop_check);
        __ bind(&loop_header);
        __ lw(scratch, MemOperand(index));
        __ Addu(index, index, Operand(-kPointerSize));
        __ push(scratch);
        __ bind(&loop_check);
        __ Branch(&loop_header, gt, index, Operand(scratch2));
    }

    // static
    void Builtins::Generate_InterpreterPushArgsThenCallImpl(
        MacroAssembler* masm, ConvertReceiverMode receiver_mode,
        InterpreterPushArgsMode mode)
    {
        DCHECK(mode != InterpreterPushArgsMode::kArrayFunction);
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a2 : the address of the first argument to be pushed. Subsequent
        //          arguments should be consecutive above this, in the same order as
        //          they are to be pushed onto the stack.
        //  -- a1 : the target to call (can be any Object).
        // -----------------------------------
        Label stack_overflow;

        __ Addu(t0, a0, Operand(1)); // Add one for receiver.

        Generate_StackOverflowCheck(masm, t0, t4, t1, &stack_overflow);

        // Push "undefined" as the receiver arg if we need to.
        if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
            __ PushRoot(RootIndex::kUndefinedValue);
            __ mov(t0, a0); // No receiver.
        }

        // This function modifies a2, t4 and t1.
        Generate_InterpreterPushArgs(masm, t0, a2, t4, t1);

        if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
            __ Pop(a2); // Pass the spread in a register
            __ Subu(a0, a0, Operand(1)); // Subtract one for spread
        }

        // Call the target.
        if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
            __ Jump(BUILTIN_CODE(masm->isolate(), CallWithSpread),
                RelocInfo::CODE_TARGET);
        } else {
            __ Jump(masm->isolate()->builtins()->Call(ConvertReceiverMode::kAny),
                RelocInfo::CODE_TARGET);
        }

        __ bind(&stack_overflow);
        {
            __ TailCallRuntime(Runtime::kThrowStackOverflow);
            // Unreachable code.
            __ break_(0xCC);
        }
    }

    // static
    void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
        MacroAssembler* masm, InterpreterPushArgsMode mode)
    {
        // ----------- S t a t e -------------
        // -- a0 : argument count (not including receiver)
        // -- a3 : new target
        // -- a1 : constructor to call
        // -- a2 : allocation site feedback if available, undefined otherwise.
        // -- t4 : address of the first argument
        // -----------------------------------
        Label stack_overflow;

        // Push a slot for the receiver.
        __ push(zero_reg);

        Generate_StackOverflowCheck(masm, a0, t1, t0, &stack_overflow);

        // This function modified t4, t1 and t0.
        Generate_InterpreterPushArgs(masm, a0, t4, t1, t0);

        if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
            __ Pop(a2); // Pass the spread in a register
            __ Subu(a0, a0, Operand(1)); // Subtract one for spread
        } else {
            __ AssertUndefinedOrAllocationSite(a2, t0);
        }

        if (mode == InterpreterPushArgsMode::kArrayFunction) {
            __ AssertFunction(a1);

            // Tail call to the array construct stub (still in the caller
            // context at this point).
            __ Jump(BUILTIN_CODE(masm->isolate(), ArrayConstructorImpl),
                RelocInfo::CODE_TARGET);
        } else if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
            // Call the constructor with a0, a1, and a3 unmodified.
            __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithSpread),
                RelocInfo::CODE_TARGET);
        } else {
            DCHECK_EQ(InterpreterPushArgsMode::kOther, mode);
            // Call the constructor with a0, a1, and a3 unmodified.
            __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
        }

        __ bind(&stack_overflow);
        {
            __ TailCallRuntime(Runtime::kThrowStackOverflow);
            // Unreachable code.
            __ break_(0xCC);
        }
    }

    static void Generate_InterpreterEnterBytecode(MacroAssembler* masm)
    {
        // Set the return address to the correct point in the interpreter entry
        // trampoline.
        Label builtin_trampoline, trampoline_loaded;
        Smi interpreter_entry_return_pc_offset(
            masm->isolate()->heap()->interpreter_entry_return_pc_offset());
        DCHECK_NE(interpreter_entry_return_pc_offset, Smi::zero());

        // If the SFI function_data is an InterpreterData, the function will have a
        // custom copy of the interpreter entry trampoline for profiling. If so,
        // get the custom trampoline, otherwise grab the entry address of the global
        // trampoline.
        __ lw(t0, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
        __ lw(t0, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
        __ lw(t0, FieldMemOperand(t0, SharedFunctionInfo::kFunctionDataOffset));
        __ GetObjectType(t0, kInterpreterDispatchTableRegister,
            kInterpreterDispatchTableRegister);
        __ Branch(&builtin_trampoline, ne, kInterpreterDispatchTableRegister,
            Operand(INTERPRETER_DATA_TYPE));

        __ lw(t0, FieldMemOperand(t0, InterpreterData::kInterpreterTrampolineOffset));
        __ Addu(t0, t0, Operand(Code::kHeaderSize - kHeapObjectTag));
        __ Branch(&trampoline_loaded);

        __ bind(&builtin_trampoline);
        __ li(t0, ExternalReference::address_of_interpreter_entry_trampoline_instruction_start(masm->isolate()));
        __ lw(t0, MemOperand(t0));

        __ bind(&trampoline_loaded);
        __ Addu(ra, t0, Operand(interpreter_entry_return_pc_offset->value()));

        // Initialize the dispatch table register.
        __ li(kInterpreterDispatchTableRegister,
            ExternalReference::interpreter_dispatch_table_address(masm->isolate()));

        // Get the bytecode array pointer from the frame.
        __ lw(kInterpreterBytecodeArrayRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));

        if (FLAG_debug_code) {
            // Check function data field is actually a BytecodeArray object.
            __ SmiTst(kInterpreterBytecodeArrayRegister, kScratchReg);
            __ Assert(ne,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                kScratchReg, Operand(zero_reg));
            __ GetObjectType(kInterpreterBytecodeArrayRegister, a1, a1);
            __ Assert(eq,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                a1, Operand(BYTECODE_ARRAY_TYPE));
        }

        // Get the target bytecode offset from the frame.
        __ lw(kInterpreterBytecodeOffsetRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
        __ SmiUntag(kInterpreterBytecodeOffsetRegister);

        // Dispatch to the target bytecode.
        __ Addu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
        __ lbu(t3, MemOperand(a1));
        __ Lsa(a1, kInterpreterDispatchTableRegister, t3, kPointerSizeLog2);
        __ lw(kJavaScriptCallCodeStartRegister, MemOperand(a1));
        __ Jump(kJavaScriptCallCodeStartRegister);
    }

    void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm)
    {
        // Advance the current bytecode offset stored within the given interpreter
        // stack frame. This simulates what all bytecode handlers do upon completion
        // of the underlying operation.
        __ lw(kInterpreterBytecodeArrayRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
        __ lw(kInterpreterBytecodeOffsetRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
        __ SmiUntag(kInterpreterBytecodeOffsetRegister);

        // Load the current bytecode.
        __ Addu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
        __ lbu(a1, MemOperand(a1));

        // Advance to the next bytecode.
        Label if_return;
        AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister, a1, a2, a3,
            &if_return);

        // Convert new bytecode offset to a Smi and save in the stackframe.
        __ SmiTag(a2, kInterpreterBytecodeOffsetRegister);
        __ sw(a2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));

        Generate_InterpreterEnterBytecode(masm);

        // We should never take the if_return path.
        __ bind(&if_return);
        __ Abort(AbortReason::kInvalidBytecodeAdvance);
    }

    void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm)
    {
        Generate_InterpreterEnterBytecode(masm);
    }

    void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0 : argument count (preserved for callee)
        //  -- a1 : new target (preserved for callee)
        //  -- a3 : target function (preserved for callee)
        // -----------------------------------
        Label failed;
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            // Preserve argument count for later compare.
            __ Move(t4, a0);
            // Push a copy of the target function and the new target.
            // Push function as parameter to the runtime call.
            __ SmiTag(a0);
            __ Push(a0, a1, a3, a1);

            // Copy arguments from caller (stdlib, foreign, heap).
            Label args_done;
            for (int j = 0; j < 4; ++j) {
                Label over;
                if (j < 3) {
                    __ Branch(&over, ne, t4, Operand(j));
                }
                for (int i = j - 1; i >= 0; --i) {
                    __ lw(t4, MemOperand(fp, StandardFrameConstants::kCallerSPOffset + i * kPointerSize));
                    __ push(t4);
                }
                for (int i = 0; i < 3 - j; ++i) {
                    __ PushRoot(RootIndex::kUndefinedValue);
                }
                if (j < 3) {
                    __ jmp(&args_done);
                    __ bind(&over);
                }
            }
            __ bind(&args_done);

            // Call runtime, on success unwind frame, and parent frame.
            __ CallRuntime(Runtime::kInstantiateAsmJs, 4);
            // A smi 0 is returned on failure, an object on success.
            __ JumpIfSmi(v0, &failed);

            __ Drop(2);
            __ pop(t4);
            __ SmiUntag(t4);
            scope.GenerateLeaveFrame();

            __ Addu(t4, t4, Operand(1));
            __ Lsa(sp, sp, t4, kPointerSizeLog2);
            __ Ret();

            __ bind(&failed);
            // Restore target function and new target.
            __ Pop(a0, a1, a3);
            __ SmiUntag(a0);
        }
        // On failure, tail call back to regular js by re-calling the function
        // which has be reset to the compile lazy builtin.
        static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
        __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
        __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
        __ Jump(a2);
    }

    namespace {
        void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
            bool java_script_builtin,
            bool with_result)
        {
            const RegisterConfiguration* config(RegisterConfiguration::Default());
            int allocatable_register_count = config->num_allocatable_general_registers();
            if (with_result) {
                // Overwrite the hole inserted by the deoptimizer with the return value from
                // the LAZY deopt point.
                __ sw(v0,
                    MemOperand(
                        sp, config->num_allocatable_general_registers() * kPointerSize + BuiltinContinuationFrameConstants::kFixedFrameSize));
            }
            for (int i = allocatable_register_count - 1; i >= 0; --i) {
                int code = config->GetAllocatableGeneralCode(i);
                __ Pop(Register::from_code(code));
                if (java_script_builtin && code == kJavaScriptCallArgCountRegister.code()) {
                    __ SmiUntag(Register::from_code(code));
                }
            }
            __ lw(fp, MemOperand(sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
            __ Pop(t0);
            __ Addu(sp, sp,
                Operand(BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
            __ Pop(ra);
            __ Addu(t0, t0, Operand(Code::kHeaderSize - kHeapObjectTag));
            __ Jump(t0);
        }
    } // namespace

    void Builtins::Generate_ContinueToCodeStubBuiltin(MacroAssembler* masm)
    {
        Generate_ContinueToBuiltinHelper(masm, false, false);
    }

    void Builtins::Generate_ContinueToCodeStubBuiltinWithResult(
        MacroAssembler* masm)
    {
        Generate_ContinueToBuiltinHelper(masm, false, true);
    }

    void Builtins::Generate_ContinueToJavaScriptBuiltin(MacroAssembler* masm)
    {
        Generate_ContinueToBuiltinHelper(masm, true, false);
    }

    void Builtins::Generate_ContinueToJavaScriptBuiltinWithResult(
        MacroAssembler* masm)
    {
        Generate_ContinueToBuiltinHelper(masm, true, true);
    }

    void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm)
    {
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            __ CallRuntime(Runtime::kNotifyDeoptimized);
        }

        DCHECK_EQ(kInterpreterAccumulatorRegister.code(), v0.code());
        __ lw(v0, MemOperand(sp, 0 * kPointerSize));
        __ Ret(USE_DELAY_SLOT);
        // Safe to fill delay slot Addu will emit one instruction.
        __ Addu(sp, sp, Operand(1 * kPointerSize)); // Remove accumulator.
    }

    void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm)
    {
        // Lookup the function in the JavaScript frame.
        __ lw(a0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
        __ lw(a0, MemOperand(a0, JavaScriptFrameConstants::kFunctionOffset));

        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            // Pass function as argument.
            __ push(a0);
            __ CallRuntime(Runtime::kCompileForOnStackReplacement);
        }

        // If the code object is null, just return to the caller.
        __ Ret(eq, v0, Operand(Smi::zero()));

        // Drop the handler frame that is be sitting on top of the actual
        // JavaScript frame. This is the case then OSR is triggered from bytecode.
        __ LeaveFrame(StackFrame::STUB);

        // Load deoptimization data from the code object.
        // <deopt_data> = <code>[#deoptimization_data_offset]
        __ lw(a1, MemOperand(v0, Code::kDeoptimizationDataOffset - kHeapObjectTag));

        // Load the OSR entrypoint offset from the deoptimization data.
        // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
        __ lw(a1, MemOperand(a1, FixedArray::OffsetOfElementAt(DeoptimizationData::kOsrPcOffsetIndex) - kHeapObjectTag));
        __ SmiUntag(a1);

        // Compute the target address = code_obj + header_size + osr_offset
        // <entry_addr> = <code_obj> + #header_size + <osr_offset>
        __ Addu(v0, v0, a1);
        __ addiu(ra, v0, Code::kHeaderSize - kHeapObjectTag);

        // And "return" to the OSR entry point of the function.
        __ Ret();
    }

    // static
    void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0    : argc
        //  -- sp[0] : argArray
        //  -- sp[4] : thisArg
        //  -- sp[8] : receiver
        // -----------------------------------

        // 1. Load receiver into a1, argArray into a0 (if present), remove all
        // arguments from the stack (including the receiver), and push thisArg (if
        // present) instead.
        {
            Label no_arg;
            Register scratch = t0;
            __ LoadRoot(a2, RootIndex::kUndefinedValue);
            __ mov(a3, a2);
            // Lsa() cannot be used hare as scratch value used later.
            __ sll(scratch, a0, kPointerSizeLog2);
            __ Addu(a0, sp, Operand(scratch));
            __ lw(a1, MemOperand(a0)); // receiver
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a2, MemOperand(a0)); // thisArg
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a3, MemOperand(a0)); // argArray
            __ bind(&no_arg);
            __ Addu(sp, sp, Operand(scratch));
            __ sw(a2, MemOperand(sp));
            __ mov(a2, a3);
        }

        // ----------- S t a t e -------------
        //  -- a2    : argArray
        //  -- a1    : receiver
        //  -- sp[0] : thisArg
        // -----------------------------------

        // 2. We don't need to check explicitly for callable receiver here,
        // since that's the first thing the Call/CallWithArrayLike builtins
        // will do.

        // 3. Tail call with no arguments if argArray is null or undefined.
        Label no_arguments;
        __ JumpIfRoot(a2, RootIndex::kNullValue, &no_arguments);
        __ JumpIfRoot(a2, RootIndex::kUndefinedValue, &no_arguments);

        // 4a. Apply the receiver to the given argArray.
        __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
            RelocInfo::CODE_TARGET);

        // 4b. The argArray is either null or undefined, so we tail call without any
        // arguments to the receiver.
        __ bind(&no_arguments);
        {
            __ mov(a0, zero_reg);
            __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
        }
    }

    // static
    void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm)
    {
        // 1. Make sure we have at least one argument.
        // a0: actual number of arguments
        {
            Label done;
            __ Branch(&done, ne, a0, Operand(zero_reg));
            __ PushRoot(RootIndex::kUndefinedValue);
            __ Addu(a0, a0, Operand(1));
            __ bind(&done);
        }

        // 2. Get the function to call (passed as receiver) from the stack.
        // a0: actual number of arguments
        __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
        __ lw(a1, MemOperand(kScratchReg));

        // 3. Shift arguments and return address one slot down on the stack
        //    (overwriting the original receiver).  Adjust argument count to make
        //    the original first argument the new receiver.
        // a0: actual number of arguments
        // a1: function
        {
            Label loop;
            // Calculate the copy start address (destination). Copy end address is sp.
            __ Lsa(a2, sp, a0, kPointerSizeLog2);

            __ bind(&loop);
            __ lw(kScratchReg, MemOperand(a2, -kPointerSize));
            __ sw(kScratchReg, MemOperand(a2));
            __ Subu(a2, a2, Operand(kPointerSize));
            __ Branch(&loop, ne, a2, Operand(sp));
            // Adjust the actual number of arguments and remove the top element
            // (which is a copy of the last argument).
            __ Subu(a0, a0, Operand(1));
            __ Pop();
        }

        // 4. Call the callable.
        __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
    }

    void Builtins::Generate_ReflectApply(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0     : argc
        //  -- sp[0]  : argumentsList
        //  -- sp[4]  : thisArgument
        //  -- sp[8]  : target
        //  -- sp[12] : receiver
        // -----------------------------------

        // 1. Load target into a1 (if present), argumentsList into a0 (if present),
        // remove all arguments from the stack (including the receiver), and push
        // thisArgument (if present) instead.
        {
            Label no_arg;
            Register scratch = t0;
            __ LoadRoot(a1, RootIndex::kUndefinedValue);
            __ mov(a2, a1);
            __ mov(a3, a1);
            __ sll(scratch, a0, kPointerSizeLog2);
            __ mov(a0, scratch);
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(zero_reg));
            __ Addu(a0, sp, Operand(a0));
            __ lw(a1, MemOperand(a0)); // target
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a2, MemOperand(a0)); // thisArgument
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a3, MemOperand(a0)); // argumentsList
            __ bind(&no_arg);
            __ Addu(sp, sp, Operand(scratch));
            __ sw(a2, MemOperand(sp));
            __ mov(a2, a3);
        }

        // ----------- S t a t e -------------
        //  -- a2    : argumentsList
        //  -- a1    : target
        //  -- sp[0] : thisArgument
        // -----------------------------------

        // 2. We don't need to check explicitly for callable target here,
        // since that's the first thing the Call/CallWithArrayLike builtins
        // will do.

        // 3. Apply the target to the given argumentsList.
        __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
            RelocInfo::CODE_TARGET);
    }

    void Builtins::Generate_ReflectConstruct(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0     : argc
        //  -- sp[0]  : new.target (optional)
        //  -- sp[4]  : argumentsList
        //  -- sp[8]  : target
        //  -- sp[12] : receiver
        // -----------------------------------

        // 1. Load target into a1 (if present), argumentsList into a0 (if present),
        // new.target into a3 (if present, otherwise use target), remove all
        // arguments from the stack (including the receiver), and push thisArgument
        // (if present) instead.
        {
            Label no_arg;
            Register scratch = t0;
            __ LoadRoot(a1, RootIndex::kUndefinedValue);
            __ mov(a2, a1);
            // Lsa() cannot be used hare as scratch value used later.
            __ sll(scratch, a0, kPointerSizeLog2);
            __ Addu(a0, sp, Operand(scratch));
            __ sw(a2, MemOperand(a0)); // receiver
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a1, MemOperand(a0)); // target
            __ mov(a3, a1); // new.target defaults to target
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a2, MemOperand(a0)); // argumentsList
            __ Subu(a0, a0, Operand(kPointerSize));
            __ Branch(&no_arg, lt, a0, Operand(sp));
            __ lw(a3, MemOperand(a0)); // new.target
            __ bind(&no_arg);
            __ Addu(sp, sp, Operand(scratch));
        }

        // ----------- S t a t e -------------
        //  -- a2    : argumentsList
        //  -- a3    : new.target
        //  -- a1    : target
        //  -- sp[0] : receiver (undefined)
        // -----------------------------------

        // 2. We don't need to check explicitly for constructor target here,
        // since that's the first thing the Construct/ConstructWithArrayLike
        // builtins will do.

        // 3. We don't need to check explicitly for constructor new.target here,
        // since that's the second thing the Construct/ConstructWithArrayLike
        // builtins will do.

        // 4. Construct the target with the given new.target and argumentsList.
        __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithArrayLike),
            RelocInfo::CODE_TARGET);
    }

    static void EnterArgumentsAdaptorFrame(MacroAssembler* masm)
    {
        __ sll(a0, a0, kSmiTagSize);
        __ li(t0, Operand(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
        __ MultiPush(a0.bit() | a1.bit() | t0.bit() | fp.bit() | ra.bit());
        __ Push(Smi::zero()); // Padding.
        __ Addu(fp, sp,
            Operand(ArgumentsAdaptorFrameConstants::kFixedFrameSizeFromFp));
    }

    static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- v0 : result being passed through
        // -----------------------------------
        // Get the number of arguments passed (as a smi), tear down the frame and
        // then tear down the parameters.
        __ lw(a1, MemOperand(fp, ArgumentsAdaptorFrameConstants::kLengthOffset));
        __ mov(sp, fp);
        __ MultiPop(fp.bit() | ra.bit());
        __ Lsa(sp, sp, a1, kPointerSizeLog2 - kSmiTagSize);
        // Adjust for the receiver.
        __ Addu(sp, sp, Operand(kPointerSize));
    }

    // static
    void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
        Handle<Code> code)
    {
        // ----------- S t a t e -------------
        //  -- a1 : target
        //  -- a0 : number of parameters on the stack (not including the receiver)
        //  -- a2 : arguments list (a FixedArray)
        //  -- t0 : len (number of elements to push from args)
        //  -- a3 : new.target (for [[Construct]])
        // -----------------------------------
        if (masm->emit_debug_code()) {
            // Allow a2 to be a FixedArray, or a FixedDoubleArray if t0 == 0.
            Label ok, fail;
            __ AssertNotSmi(a2);
            __ GetObjectType(a2, t8, t8);
            __ Branch(&ok, eq, t8, Operand(FIXED_ARRAY_TYPE));
            __ Branch(&fail, ne, t8, Operand(FIXED_DOUBLE_ARRAY_TYPE));
            __ Branch(&ok, eq, t0, Operand(0));
            // Fall through.
            __ bind(&fail);
            __ Abort(AbortReason::kOperandIsNotAFixedArray);

            __ bind(&ok);
        }

        // Check for stack overflow.
        Label stack_overflow;
        Generate_StackOverflowCheck(masm, t0, kScratchReg, t1, &stack_overflow);

        // Push arguments onto the stack (thisArgument is already on the stack).
        {
            __ mov(t2, zero_reg);
            Label done, push, loop;
            __ LoadRoot(t1, RootIndex::kTheHoleValue);
            __ bind(&loop);
            __ Branch(&done, eq, t2, Operand(t0));
            __ Lsa(kScratchReg, a2, t2, kPointerSizeLog2);
            __ lw(kScratchReg, FieldMemOperand(kScratchReg, FixedArray::kHeaderSize));
            __ Branch(&push, ne, t1, Operand(kScratchReg));
            __ LoadRoot(kScratchReg, RootIndex::kUndefinedValue);
            __ bind(&push);
            __ Push(kScratchReg);
            __ Addu(t2, t2, Operand(1));
            __ Branch(&loop);
            __ bind(&done);
            __ Addu(a0, a0, t2);
        }

        // Tail-call to the actual Call or Construct builtin.
        __ Jump(code, RelocInfo::CODE_TARGET);

        __ bind(&stack_overflow);
        __ TailCallRuntime(Runtime::kThrowStackOverflow);
    }

    // static
    void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
        CallOrConstructMode mode,
        Handle<Code> code)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a3 : the new.target (for [[Construct]] calls)
        //  -- a1 : the target to call (can be any Object)
        //  -- a2 : start index (to support rest parameters)
        // -----------------------------------

        // Check if new.target has a [[Construct]] internal method.
        if (mode == CallOrConstructMode::kConstruct) {
            Label new_target_constructor, new_target_not_constructor;
            __ JumpIfSmi(a3, &new_target_not_constructor);
            __ lw(t1, FieldMemOperand(a3, HeapObject::kMapOffset));
            __ lbu(t1, FieldMemOperand(t1, Map::kBitFieldOffset));
            __ And(t1, t1, Operand(Map::IsConstructorBit::kMask));
            __ Branch(&new_target_constructor, ne, t1, Operand(zero_reg));
            __ bind(&new_target_not_constructor);
            {
                FrameScope scope(masm, StackFrame::MANUAL);
                __ EnterFrame(StackFrame::INTERNAL);
                __ Push(a3);
                __ CallRuntime(Runtime::kThrowNotConstructor);
            }
            __ bind(&new_target_constructor);
        }

        // Check if we have an arguments adaptor frame below the function frame.
        Label arguments_adaptor, arguments_done;
        __ lw(t3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
        __ lw(t2, MemOperand(t3, CommonFrameConstants::kContextOrFrameTypeOffset));
        __ Branch(&arguments_adaptor, eq, t2,
            Operand(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
        {
            __ lw(t2, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
            __ lw(t2, FieldMemOperand(t2, JSFunction::kSharedFunctionInfoOffset));
            __ lhu(t2, FieldMemOperand(t2, SharedFunctionInfo::kFormalParameterCountOffset));
            __ mov(t3, fp);
        }
        __ Branch(&arguments_done);
        __ bind(&arguments_adaptor);
        {
            // Just get the length from the ArgumentsAdaptorFrame.
            __ lw(t2, MemOperand(t3, ArgumentsAdaptorFrameConstants::kLengthOffset));
            __ SmiUntag(t2);
        }
        __ bind(&arguments_done);

        Label stack_done, stack_overflow;
        __ Subu(t2, t2, a2);
        __ Branch(&stack_done, le, t2, Operand(zero_reg));
        {
            // Check for stack overflow.
            Generate_StackOverflowCheck(masm, t2, t0, t1, &stack_overflow);

            // Forward the arguments from the caller frame.
            {
                Label loop;
                __ Addu(a0, a0, t2);
                __ bind(&loop);
                {
                    __ Lsa(kScratchReg, t3, t2, kPointerSizeLog2);
                    __ lw(kScratchReg, MemOperand(kScratchReg, 1 * kPointerSize));
                    __ push(kScratchReg);
                    __ Subu(t2, t2, Operand(1));
                    __ Branch(&loop, ne, t2, Operand(zero_reg));
                }
            }
        }
        __ Branch(&stack_done);
        __ bind(&stack_overflow);
        __ TailCallRuntime(Runtime::kThrowStackOverflow);
        __ bind(&stack_done);

        // Tail-call to the {code} handler.
        __ Jump(code, RelocInfo::CODE_TARGET);
    }

    // static
    void Builtins::Generate_CallFunction(MacroAssembler* masm,
        ConvertReceiverMode mode)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the function to call (checked to be a JSFunction)
        // -----------------------------------
        __ AssertFunction(a1);

        // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
        // Check that the function is not a "classConstructor".
        Label class_constructor;
        __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
        __ lw(a3, FieldMemOperand(a2, SharedFunctionInfo::kFlagsOffset));
        __ And(kScratchReg, a3,
            Operand(SharedFunctionInfo::IsClassConstructorBit::kMask));
        __ Branch(&class_constructor, ne, kScratchReg, Operand(zero_reg));

        // Enter the context of the function; ToObject has to run in the function
        // context, and we also need to take the global proxy from the function
        // context in case of conversion.
        __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
        // We need to convert the receiver for non-native sloppy mode functions.
        Label done_convert;
        __ lw(a3, FieldMemOperand(a2, SharedFunctionInfo::kFlagsOffset));
        __ And(kScratchReg, a3,
            Operand(SharedFunctionInfo::IsNativeBit::kMask | SharedFunctionInfo::IsStrictBit::kMask));
        __ Branch(&done_convert, ne, kScratchReg, Operand(zero_reg));
        {
            // ----------- S t a t e -------------
            //  -- a0 : the number of arguments (not including the receiver)
            //  -- a1 : the function to call (checked to be a JSFunction)
            //  -- a2 : the shared function info.
            //  -- cp : the function context.
            // -----------------------------------

            if (mode == ConvertReceiverMode::kNullOrUndefined) {
                // Patch receiver to global proxy.
                __ LoadGlobalProxy(a3);
            } else {
                Label convert_to_object, convert_receiver;
                __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
                __ lw(a3, MemOperand(kScratchReg));
                __ JumpIfSmi(a3, &convert_to_object);
                STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
                __ GetObjectType(a3, t0, t0);
                __ Branch(&done_convert, hs, t0, Operand(FIRST_JS_RECEIVER_TYPE));
                if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
                    Label convert_global_proxy;
                    __ JumpIfRoot(a3, RootIndex::kUndefinedValue, &convert_global_proxy);
                    __ JumpIfNotRoot(a3, RootIndex::kNullValue, &convert_to_object);
                    __ bind(&convert_global_proxy);
                    {
                        // Patch receiver to global proxy.
                        __ LoadGlobalProxy(a3);
                    }
                    __ Branch(&convert_receiver);
                }
                __ bind(&convert_to_object);
                {
                    // Convert receiver using ToObject.
                    // TODO(bmeurer): Inline the allocation here to avoid building the frame
                    // in the fast case? (fall back to AllocateInNewSpace?)
                    FrameScope scope(masm, StackFrame::INTERNAL);
                    __ sll(a0, a0, kSmiTagSize); // Smi tagged.
                    __ Push(a0, a1);
                    __ mov(a0, a3);
                    __ Push(cp);
                    __ Call(BUILTIN_CODE(masm->isolate(), ToObject),
                        RelocInfo::CODE_TARGET);
                    __ Pop(cp);
                    __ mov(a3, v0);
                    __ Pop(a0, a1);
                    __ sra(a0, a0, kSmiTagSize); // Un-tag.
                }
                __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
                __ bind(&convert_receiver);
            }
            __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
            __ sw(a3, MemOperand(kScratchReg));
        }
        __ bind(&done_convert);

        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the function to call (checked to be a JSFunction)
        //  -- a2 : the shared function info.
        //  -- cp : the function context.
        // -----------------------------------

        __ lhu(a2,
            FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
        ParameterCount actual(a0);
        ParameterCount expected(a2);
        __ InvokeFunctionCode(a1, no_reg, expected, actual, JUMP_FUNCTION);

        // The function is a "classConstructor", need to raise an exception.
        __ bind(&class_constructor);
        {
            FrameScope frame(masm, StackFrame::INTERNAL);
            __ Push(a1);
            __ CallRuntime(Runtime::kThrowConstructorNonCallableError);
        }
    }

    // static
    void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the function to call (checked to be a JSBoundFunction)
        // -----------------------------------
        __ AssertBoundFunction(a1);

        // Patch the receiver to [[BoundThis]].
        {
            __ lw(kScratchReg, FieldMemOperand(a1, JSBoundFunction::kBoundThisOffset));
            __ Lsa(t0, sp, a0, kPointerSizeLog2);
            __ sw(kScratchReg, MemOperand(t0));
        }

        // Load [[BoundArguments]] into a2 and length of that into t0.
        __ lw(a2, FieldMemOperand(a1, JSBoundFunction::kBoundArgumentsOffset));
        __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
        __ SmiUntag(t0);

        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the function to call (checked to be a JSBoundFunction)
        //  -- a2 : the [[BoundArguments]] (implemented as FixedArray)
        //  -- t0 : the number of [[BoundArguments]]
        // -----------------------------------

        // Reserve stack space for the [[BoundArguments]].
        {
            Label done;
            __ sll(t1, t0, kPointerSizeLog2);
            __ Subu(sp, sp, Operand(t1));
            // Check the stack for overflow. We are not trying to catch interruptions
            // (i.e. debug break and preemption) here, so check the "real stack limit".
            __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
            __ Branch(&done, hs, sp, Operand(kScratchReg));
            // Restore the stack pointer.
            __ Addu(sp, sp, Operand(t1));
            {
                FrameScope scope(masm, StackFrame::MANUAL);
                __ EnterFrame(StackFrame::INTERNAL);
                __ CallRuntime(Runtime::kThrowStackOverflow);
            }
            __ bind(&done);
        }

        // Relocate arguments down the stack.
        {
            Label loop, done_loop;
            __ mov(t1, zero_reg);
            __ bind(&loop);
            __ Branch(&done_loop, gt, t1, Operand(a0));
            __ Lsa(t2, sp, t0, kPointerSizeLog2);
            __ lw(kScratchReg, MemOperand(t2));
            __ Lsa(t2, sp, t1, kPointerSizeLog2);
            __ sw(kScratchReg, MemOperand(t2));
            __ Addu(t0, t0, Operand(1));
            __ Addu(t1, t1, Operand(1));
            __ Branch(&loop);
            __ bind(&done_loop);
        }

        // Copy [[BoundArguments]] to the stack (below the arguments).
        {
            Label loop, done_loop;
            __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
            __ SmiUntag(t0);
            __ Addu(a2, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
            __ bind(&loop);
            __ Subu(t0, t0, Operand(1));
            __ Branch(&done_loop, lt, t0, Operand(zero_reg));
            __ Lsa(t1, a2, t0, kPointerSizeLog2);
            __ lw(kScratchReg, MemOperand(t1));
            __ Lsa(t1, sp, a0, kPointerSizeLog2);
            __ sw(kScratchReg, MemOperand(t1));
            __ Addu(a0, a0, Operand(1));
            __ Branch(&loop);
            __ bind(&done_loop);
        }

        // Call the [[BoundTargetFunction]] via the Call builtin.
        __ lw(a1, FieldMemOperand(a1, JSBoundFunction::kBoundTargetFunctionOffset));
        __ Jump(BUILTIN_CODE(masm->isolate(), Call_ReceiverIsAny),
            RelocInfo::CODE_TARGET);
    }

    // static
    void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the target to call (can be any Object).
        // -----------------------------------

        Label non_callable, non_function, non_smi;
        __ JumpIfSmi(a1, &non_callable);
        __ bind(&non_smi);
        __ GetObjectType(a1, t1, t2);
        __ Jump(masm->isolate()->builtins()->CallFunction(mode),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_FUNCTION_TYPE));
        __ Jump(BUILTIN_CODE(masm->isolate(), CallBoundFunction),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_BOUND_FUNCTION_TYPE));

        // Check if target has a [[Call]] internal method.
        __ lbu(t1, FieldMemOperand(t1, Map::kBitFieldOffset));
        __ And(t1, t1, Operand(Map::IsCallableBit::kMask));
        __ Branch(&non_callable, eq, t1, Operand(zero_reg));

        // Check if target is a proxy and call CallProxy external builtin
        __ Branch(&non_function, ne, t2, Operand(JS_PROXY_TYPE));
        __ Jump(BUILTIN_CODE(masm->isolate(), CallProxy), RelocInfo::CODE_TARGET);

        // 2. Call to something else, which might have a [[Call]] internal method (if
        // not we raise an exception).
        __ bind(&non_function);
        // Overwrite the original receiver with the (original) target.
        __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
        __ sw(a1, MemOperand(kScratchReg));
        // Let the "call_as_function_delegate" take care of the rest.
        __ LoadNativeContextSlot(Context::CALL_AS_FUNCTION_DELEGATE_INDEX, a1);
        __ Jump(masm->isolate()->builtins()->CallFunction(
                    ConvertReceiverMode::kNotNullOrUndefined),
            RelocInfo::CODE_TARGET);

        // 3. Call to something that is not callable.
        __ bind(&non_callable);
        {
            FrameScope scope(masm, StackFrame::INTERNAL);
            __ Push(a1);
            __ CallRuntime(Runtime::kThrowCalledNonCallable);
        }
    }

    // static
    void Builtins::Generate_ConstructFunction(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the constructor to call (checked to be a JSFunction)
        //  -- a3 : the new target (checked to be a constructor)
        // -----------------------------------
        __ AssertConstructor(a1);
        __ AssertFunction(a1);

        // Calling convention for function specific ConstructStubs require
        // a2 to contain either an AllocationSite or undefined.
        __ LoadRoot(a2, RootIndex::kUndefinedValue);

        Label call_generic_stub;

        // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
        __ lw(t0, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
        __ lw(t0, FieldMemOperand(t0, SharedFunctionInfo::kFlagsOffset));
        __ And(t0, t0, Operand(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
        __ Branch(&call_generic_stub, eq, t0, Operand(zero_reg));

        __ Jump(BUILTIN_CODE(masm->isolate(), JSBuiltinsConstructStub),
            RelocInfo::CODE_TARGET);

        __ bind(&call_generic_stub);
        __ Jump(BUILTIN_CODE(masm->isolate(), JSConstructStubGeneric),
            RelocInfo::CODE_TARGET);
    }

    // static
    void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the function to call (checked to be a JSBoundFunction)
        //  -- a3 : the new target (checked to be a constructor)
        // -----------------------------------
        __ AssertConstructor(a1);
        __ AssertBoundFunction(a1);

        // Load [[BoundArguments]] into a2 and length of that into t0.
        __ lw(a2, FieldMemOperand(a1, JSBoundFunction::kBoundArgumentsOffset));
        __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
        __ SmiUntag(t0);

        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the function to call (checked to be a JSBoundFunction)
        //  -- a2 : the [[BoundArguments]] (implemented as FixedArray)
        //  -- a3 : the new target (checked to be a constructor)
        //  -- t0 : the number of [[BoundArguments]]
        // -----------------------------------

        // Reserve stack space for the [[BoundArguments]].
        {
            Label done;
            __ sll(t1, t0, kPointerSizeLog2);
            __ Subu(sp, sp, Operand(t1));
            // Check the stack for overflow. We are not trying to catch interruptions
            // (i.e. debug break and preemption) here, so check the "real stack limit".
            __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
            __ Branch(&done, hs, sp, Operand(kScratchReg));
            // Restore the stack pointer.
            __ Addu(sp, sp, Operand(t1));
            {
                FrameScope scope(masm, StackFrame::MANUAL);
                __ EnterFrame(StackFrame::INTERNAL);
                __ CallRuntime(Runtime::kThrowStackOverflow);
            }
            __ bind(&done);
        }

        // Relocate arguments down the stack.
        {
            Label loop, done_loop;
            __ mov(t1, zero_reg);
            __ bind(&loop);
            __ Branch(&done_loop, ge, t1, Operand(a0));
            __ Lsa(t2, sp, t0, kPointerSizeLog2);
            __ lw(kScratchReg, MemOperand(t2));
            __ Lsa(t2, sp, t1, kPointerSizeLog2);
            __ sw(kScratchReg, MemOperand(t2));
            __ Addu(t0, t0, Operand(1));
            __ Addu(t1, t1, Operand(1));
            __ Branch(&loop);
            __ bind(&done_loop);
        }

        // Copy [[BoundArguments]] to the stack (below the arguments).
        {
            Label loop, done_loop;
            __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
            __ SmiUntag(t0);
            __ Addu(a2, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
            __ bind(&loop);
            __ Subu(t0, t0, Operand(1));
            __ Branch(&done_loop, lt, t0, Operand(zero_reg));
            __ Lsa(t1, a2, t0, kPointerSizeLog2);
            __ lw(kScratchReg, MemOperand(t1));
            __ Lsa(t1, sp, a0, kPointerSizeLog2);
            __ sw(kScratchReg, MemOperand(t1));
            __ Addu(a0, a0, Operand(1));
            __ Branch(&loop);
            __ bind(&done_loop);
        }

        // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
        {
            Label skip_load;
            __ Branch(&skip_load, ne, a1, Operand(a3));
            __ lw(a3, FieldMemOperand(a1, JSBoundFunction::kBoundTargetFunctionOffset));
            __ bind(&skip_load);
        }

        // Construct the [[BoundTargetFunction]] via the Construct builtin.
        __ lw(a1, FieldMemOperand(a1, JSBoundFunction::kBoundTargetFunctionOffset));
        __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
    }

    // static
    void Builtins::Generate_Construct(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0 : the number of arguments (not including the receiver)
        //  -- a1 : the constructor to call (can be any Object)
        //  -- a3 : the new target (either the same as the constructor or
        //          the JSFunction on which new was invoked initially)
        // -----------------------------------

        // Check if target is a Smi.
        Label non_constructor, non_proxy;
        __ JumpIfSmi(a1, &non_constructor);

        // Check if target has a [[Construct]] internal method.
        __ lw(t1, FieldMemOperand(a1, HeapObject::kMapOffset));
        __ lbu(t3, FieldMemOperand(t1, Map::kBitFieldOffset));
        __ And(t3, t3, Operand(Map::IsConstructorBit::kMask));
        __ Branch(&non_constructor, eq, t3, Operand(zero_reg));

        // Dispatch based on instance type.
        __ lhu(t2, FieldMemOperand(t1, Map::kInstanceTypeOffset));
        __ Jump(BUILTIN_CODE(masm->isolate(), ConstructFunction),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_FUNCTION_TYPE));

        // Only dispatch to bound functions after checking whether they are
        // constructors.
        __ Jump(BUILTIN_CODE(masm->isolate(), ConstructBoundFunction),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_BOUND_FUNCTION_TYPE));

        // Only dispatch to proxies after checking whether they are constructors.
        __ Branch(&non_proxy, ne, t2, Operand(JS_PROXY_TYPE));
        __ Jump(BUILTIN_CODE(masm->isolate(), ConstructProxy),
            RelocInfo::CODE_TARGET);

        // Called Construct on an exotic Object with a [[Construct]] internal method.
        __ bind(&non_proxy);
        {
            // Overwrite the original receiver with the (original) target.
            __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
            __ sw(a1, MemOperand(kScratchReg));
            // Let the "call_as_constructor_delegate" take care of the rest.
            __ LoadNativeContextSlot(Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, a1);
            __ Jump(masm->isolate()->builtins()->CallFunction(),
                RelocInfo::CODE_TARGET);
        }

        // Called Construct on an Object that doesn't have a [[Construct]] internal
        // method.
        __ bind(&non_constructor);
        __ Jump(BUILTIN_CODE(masm->isolate(), ConstructedNonConstructable),
            RelocInfo::CODE_TARGET);
    }

    void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm)
    {
        // State setup as expected by MacroAssembler::InvokePrologue.
        // ----------- S t a t e -------------
        //  -- a0: actual arguments count
        //  -- a1: function (passed through to callee)
        //  -- a2: expected arguments count
        //  -- a3: new target (passed through to callee)
        // -----------------------------------

        Label invoke, dont_adapt_arguments, stack_overflow;

        Label enough, too_few;
        __ Branch(&dont_adapt_arguments, eq, a2,
            Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
        // We use Uless as the number of argument should always be greater than 0.
        __ Branch(&too_few, Uless, a0, Operand(a2));

        { // Enough parameters: actual >= expected.
            // a0: actual number of arguments as a smi
            // a1: function
            // a2: expected number of arguments
            // a3: new target (passed through to callee)
            __ bind(&enough);
            EnterArgumentsAdaptorFrame(masm);
            Generate_StackOverflowCheck(masm, a2, t1, kScratchReg, &stack_overflow);

            // Calculate copy start address into a0 and copy end address into t1.
            __ Lsa(a0, fp, a0, kPointerSizeLog2 - kSmiTagSize);
            // Adjust for return address and receiver.
            __ Addu(a0, a0, Operand(2 * kPointerSize));
            // Compute copy end address.
            __ sll(t1, a2, kPointerSizeLog2);
            __ subu(t1, a0, t1);

            // Copy the arguments (including the receiver) to the new stack frame.
            // a0: copy start address
            // a1: function
            // a2: expected number of arguments
            // a3: new target (passed through to callee)
            // t1: copy end address

            Label copy;
            __ bind(&copy);
            __ lw(t0, MemOperand(a0));
            __ push(t0);
            __ Branch(USE_DELAY_SLOT, &copy, ne, a0, Operand(t1));
            __ addiu(a0, a0, -kPointerSize); // In delay slot.

            __ jmp(&invoke);
        }

        { // Too few parameters: Actual < expected.
            __ bind(&too_few);
            EnterArgumentsAdaptorFrame(masm);
            Generate_StackOverflowCheck(masm, a2, t1, kScratchReg, &stack_overflow);

            // Calculate copy start address into a0 and copy end address into t3.
            // a0: actual number of arguments as a smi
            // a1: function
            // a2: expected number of arguments
            // a3: new target (passed through to callee)
            __ Lsa(a0, fp, a0, kPointerSizeLog2 - kSmiTagSize);
            // Adjust for return address and receiver.
            __ Addu(a0, a0, Operand(2 * kPointerSize));
            // Compute copy end address. Also adjust for return address.
            __ Addu(t3, fp, kPointerSize);

            // Copy the arguments (including the receiver) to the new stack frame.
            // a0: copy start address
            // a1: function
            // a2: expected number of arguments
            // a3: new target (passed through to callee)
            // t3: copy end address
            Label copy;
            __ bind(&copy);
            __ lw(t0, MemOperand(a0)); // Adjusted above for return addr and receiver.
            __ Subu(sp, sp, kPointerSize);
            __ Subu(a0, a0, kPointerSize);
            __ Branch(USE_DELAY_SLOT, &copy, ne, a0, Operand(t3));
            __ sw(t0, MemOperand(sp)); // In the delay slot.

            // Fill the remaining expected arguments with undefined.
            // a1: function
            // a2: expected number of arguments
            // a3: new target (passed through to callee)
            __ LoadRoot(t0, RootIndex::kUndefinedValue);
            __ sll(t2, a2, kPointerSizeLog2);
            __ Subu(t1, fp, Operand(t2));
            // Adjust for frame.
            __ Subu(t1, t1,
                Operand(ArgumentsAdaptorFrameConstants::kFixedFrameSizeFromFp + kPointerSize));

            Label fill;
            __ bind(&fill);
            __ Subu(sp, sp, kPointerSize);
            __ Branch(USE_DELAY_SLOT, &fill, ne, sp, Operand(t1));
            __ sw(t0, MemOperand(sp));
        }

        // Call the entry point.
        __ bind(&invoke);
        __ mov(a0, a2);
        // a0 : expected number of arguments
        // a1 : function (passed through to callee)
        // a3 : new target (passed through to callee)
        static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
        __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
        __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
        __ Call(a2);

        // Store offset of return address for deoptimizer.
        masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(masm->pc_offset());

        // Exit frame and return.
        LeaveArgumentsAdaptorFrame(masm);
        __ Ret();

        // -------------------------------------------
        // Don't adapt arguments.
        // -------------------------------------------
        __ bind(&dont_adapt_arguments);
        static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
        __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
        __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
        __ Jump(a2);

        __ bind(&stack_overflow);
        {
            FrameScope frame(masm, StackFrame::MANUAL);
            __ CallRuntime(Runtime::kThrowStackOverflow);
            __ break_(0xCC);
        }
    }

    void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm)
    {
        // The function index was put in t0 by the jump table trampoline.
        // Convert to Smi for the runtime call.
        __ SmiTag(kWasmCompileLazyFuncIndexRegister);
        {
            HardAbortScope hard_abort(masm); // Avoid calls to Abort.
            FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);

            // Save all parameter registers (see wasm-linkage.cc). They might be
            // overwritten in the runtime call below. We don't have any callee-saved
            // registers in wasm, so no need to store anything else.
            constexpr RegList gp_regs = Register::ListOf<a0, a1, a2, a3>();
            constexpr RegList fp_regs = DoubleRegister::ListOf<f2, f4, f6, f8, f10, f12, f14>();
            __ MultiPush(gp_regs);
            __ MultiPushFPU(fp_regs);

            // Pass instance and function index as an explicit arguments to the runtime
            // function.
            __ Push(kWasmInstanceRegister, kWasmCompileLazyFuncIndexRegister);
            // Load the correct CEntry builtin from the instance object.
            __ lw(a2, FieldMemOperand(kWasmInstanceRegister, WasmInstanceObject::kCEntryStubOffset));
            // Initialize the JavaScript context with 0. CEntry will use it to
            // set the current context on the isolate.
            __ Move(kContextRegister, Smi::zero());
            __ CallRuntimeWithCEntry(Runtime::kWasmCompileLazy, a2);

            // Restore registers.
            __ MultiPopFPU(fp_regs);
            __ MultiPop(gp_regs);
        }
        // Finally, jump to the entrypoint.
        __ Jump(kScratchReg, v0, 0);
    }

    void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
        SaveFPRegsMode save_doubles, ArgvMode argv_mode,
        bool builtin_exit_frame)
    {
        // Called from JavaScript; parameters are on stack as if calling JS function
        // a0: number of arguments including receiver
        // a1: pointer to builtin function
        // fp: frame pointer    (restored after C call)
        // sp: stack pointer    (restored as callee's sp after C call)
        // cp: current context  (C callee-saved)
        //
        // If argv_mode == kArgvInRegister:
        // a2: pointer to the first argument

        if (argv_mode == kArgvInRegister) {
            // Move argv into the correct register.
            __ mov(s1, a2);
        } else {
            // Compute the argv pointer in a callee-saved register.
            __ Lsa(s1, sp, a0, kPointerSizeLog2);
            __ Subu(s1, s1, kPointerSize);
        }

        // Enter the exit frame that transitions from JavaScript to C++.
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterExitFrame(
            save_doubles == kSaveFPRegs, 0,
            builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);

        // s0: number of arguments  including receiver (C callee-saved)
        // s1: pointer to first argument (C callee-saved)
        // s2: pointer to builtin function (C callee-saved)

        // Prepare arguments for C routine.
        // a0 = argc
        __ mov(s0, a0);
        __ mov(s2, a1);

        // We are calling compiled C/C++ code. a0 and a1 hold our two arguments. We
        // also need to reserve the 4 argument slots on the stack.

        __ AssertStackIsAligned();

        // a0 = argc, a1 = argv, a2 = isolate
        __ li(a2, ExternalReference::isolate_address(masm->isolate()));
        __ mov(a1, s1);

        __ StoreReturnAddressAndCall(s2);

        // Result returned in v0 or v1:v0 - do not destroy these registers!

        // Check result for exception sentinel.
        Label exception_returned;
        __ LoadRoot(t0, RootIndex::kException);
        __ Branch(&exception_returned, eq, t0, Operand(v0));

        // Check that there is no pending exception, otherwise we
        // should have returned the exception sentinel.
        if (FLAG_debug_code) {
            Label okay;
            ExternalReference pending_exception_address = ExternalReference::Create(
                IsolateAddressId::kPendingExceptionAddress, masm->isolate());
            __ li(a2, pending_exception_address);
            __ lw(a2, MemOperand(a2));
            __ LoadRoot(t0, RootIndex::kTheHoleValue);
            // Cannot use check here as it attempts to generate call into runtime.
            __ Branch(&okay, eq, t0, Operand(a2));
            __ stop("Unexpected pending exception");
            __ bind(&okay);
        }

        // Exit C frame and return.
        // v0:v1: result
        // sp: stack pointer
        // fp: frame pointer
        Register argc = argv_mode == kArgvInRegister
            // We don't want to pop arguments so set argc to no_reg.
            ? no_reg
            // s0: still holds argc (callee-saved).
            : s0;
        __ LeaveExitFrame(save_doubles == kSaveFPRegs, argc, EMIT_RETURN);

        // Handling of exception.
        __ bind(&exception_returned);

        ExternalReference pending_handler_context_address = ExternalReference::Create(
            IsolateAddressId::kPendingHandlerContextAddress, masm->isolate());
        ExternalReference pending_handler_entrypoint_address = ExternalReference::Create(
            IsolateAddressId::kPendingHandlerEntrypointAddress, masm->isolate());
        ExternalReference pending_handler_fp_address = ExternalReference::Create(
            IsolateAddressId::kPendingHandlerFPAddress, masm->isolate());
        ExternalReference pending_handler_sp_address = ExternalReference::Create(
            IsolateAddressId::kPendingHandlerSPAddress, masm->isolate());

        // Ask the runtime for help to determine the handler. This will set v0 to
        // contain the current pending exception, don't clobber it.
        ExternalReference find_handler = ExternalReference::Create(Runtime::kUnwindAndFindExceptionHandler);
        {
            FrameScope scope(masm, StackFrame::MANUAL);
            __ PrepareCallCFunction(3, 0, a0);
            __ mov(a0, zero_reg);
            __ mov(a1, zero_reg);
            __ li(a2, ExternalReference::isolate_address(masm->isolate()));
            __ CallCFunction(find_handler, 3);
        }

        // Retrieve the handler context, SP and FP.
        __ li(cp, pending_handler_context_address);
        __ lw(cp, MemOperand(cp));
        __ li(sp, pending_handler_sp_address);
        __ lw(sp, MemOperand(sp));
        __ li(fp, pending_handler_fp_address);
        __ lw(fp, MemOperand(fp));

        // If the handler is a JS frame, restore the context to the frame. Note that
        // the context will be set to (cp == 0) for non-JS frames.
        Label zero;
        __ Branch(&zero, eq, cp, Operand(zero_reg));
        __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
        __ bind(&zero);

        // Reset the masking register. This is done independent of the underlying
        // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
        // with both configurations. It is safe to always do this, because the
        // underlying register is caller-saved and can be arbitrarily clobbered.
        __ ResetSpeculationPoisonRegister();

        // Compute the handler entry address and jump to it.
        __ li(t9, pending_handler_entrypoint_address);
        __ lw(t9, MemOperand(t9));
        __ Jump(t9);
    }

    void Builtins::Generate_DoubleToI(MacroAssembler* masm)
    {
        Label done;
        Register result_reg = t0;

        Register scratch = GetRegisterThatIsNotOneOf(result_reg);
        Register scratch2 = GetRegisterThatIsNotOneOf(result_reg, scratch);
        Register scratch3 = GetRegisterThatIsNotOneOf(result_reg, scratch, scratch2);
        DoubleRegister double_scratch = kScratchDoubleReg;

        // Account for saved regs.
        const int kArgumentOffset = 4 * kPointerSize;

        __ Push(result_reg);
        __ Push(scratch, scratch2, scratch3);

        // Load double input.
        __ Ldc1(double_scratch, MemOperand(sp, kArgumentOffset));

        // Clear cumulative exception flags and save the FCSR.
        __ cfc1(scratch2, FCSR);
        __ ctc1(zero_reg, FCSR);

        // Try a conversion to a signed integer.
        __ Trunc_w_d(double_scratch, double_scratch);
        // Move the converted value into the result register.
        __ mfc1(scratch3, double_scratch);

        // Retrieve and restore the FCSR.
        __ cfc1(scratch, FCSR);
        __ ctc1(scratch2, FCSR);

        // Check for overflow and NaNs.
        __ And(
            scratch, scratch,
            kFCSROverflowFlagMask | kFCSRUnderflowFlagMask | kFCSRInvalidOpFlagMask);
        // If we had no exceptions then set result_reg and we are done.
        Label error;
        __ Branch(&error, ne, scratch, Operand(zero_reg));
        __ Move(result_reg, scratch3);
        __ Branch(&done);
        __ bind(&error);

        // Load the double value and perform a manual truncation.
        Register input_high = scratch2;
        Register input_low = scratch3;

        __ lw(input_low, MemOperand(sp, kArgumentOffset + Register::kMantissaOffset));
        __ lw(input_high,
            MemOperand(sp, kArgumentOffset + Register::kExponentOffset));

        Label normal_exponent;
        // Extract the biased exponent in result.
        __ Ext(result_reg, input_high, HeapNumber::kExponentShift,
            HeapNumber::kExponentBits);

        // Check for Infinity and NaNs, which should return 0.
        __ Subu(scratch, result_reg, HeapNumber::kExponentMask);
        __ Movz(result_reg, zero_reg, scratch);
        __ Branch(&done, eq, scratch, Operand(zero_reg));

        // Express exponent as delta to (number of mantissa bits + 31).
        __ Subu(result_reg, result_reg,
            Operand(HeapNumber::kExponentBias + HeapNumber::kMantissaBits + 31));

        // If the delta is strictly positive, all bits would be shifted away,
        // which means that we can return 0.
        __ Branch(&normal_exponent, le, result_reg, Operand(zero_reg));
        __ mov(result_reg, zero_reg);
        __ Branch(&done);

        __ bind(&normal_exponent);
        const int kShiftBase = HeapNumber::kNonMantissaBitsInTopWord - 1;
        // Calculate shift.
        __ Addu(scratch, result_reg, Operand(kShiftBase + HeapNumber::kMantissaBits));

        // Save the sign.
        Register sign = result_reg;
        result_reg = no_reg;
        __ And(sign, input_high, Operand(HeapNumber::kSignMask));

        // On ARM shifts > 31 bits are valid and will result in zero. On MIPS we need
        // to check for this specific case.
        Label high_shift_needed, high_shift_done;
        __ Branch(&high_shift_needed, lt, scratch, Operand(32));
        __ mov(input_high, zero_reg);
        __ Branch(&high_shift_done);
        __ bind(&high_shift_needed);

        // Set the implicit 1 before the mantissa part in input_high.
        __ Or(input_high, input_high,
            Operand(1 << HeapNumber::kMantissaBitsInTopWord));
        // Shift the mantissa bits to the correct position.
        // We don't need to clear non-mantissa bits as they will be shifted away.
        // If they weren't, it would mean that the answer is in the 32bit range.
        __ sllv(input_high, input_high, scratch);

        __ bind(&high_shift_done);

        // Replace the shifted bits with bits from the lower mantissa word.
        Label pos_shift, shift_done;
        __ li(kScratchReg, 32);
        __ subu(scratch, kScratchReg, scratch);
        __ Branch(&pos_shift, ge, scratch, Operand(zero_reg));

        // Negate scratch.
        __ Subu(scratch, zero_reg, scratch);
        __ sllv(input_low, input_low, scratch);
        __ Branch(&shift_done);

        __ bind(&pos_shift);
        __ srlv(input_low, input_low, scratch);

        __ bind(&shift_done);
        __ Or(input_high, input_high, Operand(input_low));
        // Restore sign if necessary.
        __ mov(scratch, sign);
        result_reg = sign;
        sign = no_reg;
        __ Subu(result_reg, zero_reg, input_high);
        __ Movz(result_reg, input_high, scratch);

        __ bind(&done);
        __ sw(result_reg, MemOperand(sp, kArgumentOffset));
        __ Pop(scratch, scratch2, scratch3);
        __ Pop(result_reg);
        __ Ret();
    }

    void Builtins::Generate_InternalArrayConstructorImpl(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- a0 : argc
        //  -- a1 : constructor
        //  -- sp[0] : return address
        //  -- sp[4] : last argument
        // -----------------------------------

        if (FLAG_debug_code) {
            // The array construct code is only set for the global and natives
            // builtin Array functions which always have maps.

            // Initial map for the builtin Array function should be a map.
            __ lw(a3, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
            // Will both indicate a nullptr and a Smi.
            __ SmiTst(a3, kScratchReg);
            __ Assert(ne, AbortReason::kUnexpectedInitialMapForArrayFunction,
                kScratchReg, Operand(zero_reg));
            __ GetObjectType(a3, a3, t0);
            __ Assert(eq, AbortReason::kUnexpectedInitialMapForArrayFunction, t0,
                Operand(MAP_TYPE));

            // Figure out the right elements kind.
            __ lw(a3, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));

            // Load the map's "bit field 2" into a3. We only need the first byte,
            // but the following bit field extraction takes care of that anyway.
            __ lbu(a3, FieldMemOperand(a3, Map::kBitField2Offset));
            // Retrieve elements_kind from bit field 2.
            __ DecodeField<Map::ElementsKindBits>(a3);

            // Initial elements kind should be packed elements.
            __ Assert(eq, AbortReason::kInvalidElementsKindForInternalPackedArray, a3,
                Operand(PACKED_ELEMENTS));

            // No arguments should be passed.
            __ Assert(eq, AbortReason::kWrongNumberOfArgumentsForInternalPackedArray,
                a0, Operand(0));
        }

        __ Jump(
            BUILTIN_CODE(masm->isolate(), InternalArrayNoArgumentConstructor_Packed),
            RelocInfo::CODE_TARGET);
    }

    namespace {

        int AddressOffset(ExternalReference ref0, ExternalReference ref1)
        {
            return ref0.address() - ref1.address();
        }

        // Calls an API function.  Allocates HandleScope, extracts returned value
        // from handle and propagates exceptions.  Restores context.  stack_space
        // - space to be unwound on exit (includes the call JS arguments space and
        // the additional space allocated for the fast call).
        void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
            ExternalReference thunk_ref, int stack_space,
            MemOperand* stack_space_operand,
            MemOperand return_value_operand)
        {
            Isolate* isolate = masm->isolate();
            ExternalReference next_address = ExternalReference::handle_scope_next_address(isolate);
            const int kNextOffset = 0;
            const int kLimitOffset = AddressOffset(
                ExternalReference::handle_scope_limit_address(isolate), next_address);
            const int kLevelOffset = AddressOffset(
                ExternalReference::handle_scope_level_address(isolate), next_address);

            DCHECK(function_address == a1 || function_address == a2);

            Label profiler_disabled;
            Label end_profiler_check;
            __ li(t9, ExternalReference::is_profiling_address(isolate));
            __ lb(t9, MemOperand(t9, 0));
            __ Branch(&profiler_disabled, eq, t9, Operand(zero_reg));

            // Additional parameter is the address of the actual callback.
            __ li(t9, thunk_ref);
            __ jmp(&end_profiler_check);

            __ bind(&profiler_disabled);
            __ mov(t9, function_address);
            __ bind(&end_profiler_check);

            // Allocate HandleScope in callee-save registers.
            __ li(s5, next_address);
            __ lw(s0, MemOperand(s5, kNextOffset));
            __ lw(s1, MemOperand(s5, kLimitOffset));
            __ lw(s2, MemOperand(s5, kLevelOffset));
            __ Addu(s2, s2, Operand(1));
            __ sw(s2, MemOperand(s5, kLevelOffset));

            if (FLAG_log_timer_events) {
                FrameScope frame(masm, StackFrame::MANUAL);
                __ PushSafepointRegisters();
                __ PrepareCallCFunction(1, a0);
                __ li(a0, ExternalReference::isolate_address(isolate));
                __ CallCFunction(ExternalReference::log_enter_external_function(), 1);
                __ PopSafepointRegisters();
            }

            __ StoreReturnAddressAndCall(t9);

            if (FLAG_log_timer_events) {
                FrameScope frame(masm, StackFrame::MANUAL);
                __ PushSafepointRegisters();
                __ PrepareCallCFunction(1, a0);
                __ li(a0, ExternalReference::isolate_address(isolate));
                __ CallCFunction(ExternalReference::log_leave_external_function(), 1);
                __ PopSafepointRegisters();
            }

            Label promote_scheduled_exception;
            Label delete_allocated_handles;
            Label leave_exit_frame;
            Label return_value_loaded;

            // Load value from ReturnValue.
            __ lw(v0, return_value_operand);
            __ bind(&return_value_loaded);

            // No more valid handles (the result handle was the last one). Restore
            // previous handle scope.
            __ sw(s0, MemOperand(s5, kNextOffset));
            if (__ emit_debug_code()) {
                __ lw(a1, MemOperand(s5, kLevelOffset));
                __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall, a1,
                    Operand(s2));
            }
            __ Subu(s2, s2, Operand(1));
            __ sw(s2, MemOperand(s5, kLevelOffset));
            __ lw(kScratchReg, MemOperand(s5, kLimitOffset));
            __ Branch(&delete_allocated_handles, ne, s1, Operand(kScratchReg));

            // Leave the API exit frame.
            __ bind(&leave_exit_frame);

            if (stack_space_operand == nullptr) {
                DCHECK_NE(stack_space, 0);
                __ li(s0, Operand(stack_space));
            } else {
                DCHECK_EQ(stack_space, 0);
                // The ExitFrame contains four MIPS argument slots after the call so this
                // must be accounted for.
                // TODO(jgruber): Investigate if this is needed by the direct call.
                __ Drop(kCArgSlotCount);
                __ lw(s0, *stack_space_operand);
            }

            static constexpr bool kDontSaveDoubles = false;
            static constexpr bool kRegisterContainsSlotCount = false;
            __ LeaveExitFrame(kDontSaveDoubles, s0, NO_EMIT_RETURN,
                kRegisterContainsSlotCount);

            // Check if the function scheduled an exception.
            __ LoadRoot(t0, RootIndex::kTheHoleValue);
            __ li(kScratchReg, ExternalReference::scheduled_exception_address(isolate));
            __ lw(t1, MemOperand(kScratchReg));
            __ Branch(&promote_scheduled_exception, ne, t0, Operand(t1));

            __ Ret();

            // Re-throw by promoting a scheduled exception.
            __ bind(&promote_scheduled_exception);
            __ TailCallRuntime(Runtime::kPromoteScheduledException);

            // HandleScope limit has changed. Delete allocated extensions.
            __ bind(&delete_allocated_handles);
            __ sw(s1, MemOperand(s5, kLimitOffset));
            __ mov(s0, v0);
            __ mov(a0, v0);
            __ PrepareCallCFunction(1, s1);
            __ li(a0, ExternalReference::isolate_address(isolate));
            __ CallCFunction(ExternalReference::delete_handle_scope_extensions(), 1);
            __ mov(v0, s0);
            __ jmp(&leave_exit_frame);
        }

    } // namespace

    void Builtins::Generate_CallApiCallback(MacroAssembler* masm)
    {
        // ----------- S t a t e -------------
        //  -- cp                  : context
        //  -- a1                  : api function address
        //  -- a2                  : arguments count (not including the receiver)
        //  -- a3                  : call data
        //  -- a0                  : holder
        //  --
        //  -- sp[0]               : last argument
        //  -- ...
        //  -- sp[(argc - 1) * 4]  : first argument
        //  -- sp[(argc + 0) * 4]  : receiver
        // -----------------------------------

        Register api_function_address = a1;
        Register argc = a2;
        Register call_data = a3;
        Register holder = a0;
        Register scratch = t0;
        Register base = t1; // For addressing MemOperands on the stack.

        DCHECK(!AreAliased(api_function_address, argc, call_data,
            holder, scratch, base));

        typedef FunctionCallbackArguments FCA;

        STATIC_ASSERT(FCA::kArgsLength == 6);
        STATIC_ASSERT(FCA::kNewTargetIndex == 5);
        STATIC_ASSERT(FCA::kDataIndex == 4);
        STATIC_ASSERT(FCA::kReturnValueOffset == 3);
        STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
        STATIC_ASSERT(FCA::kIsolateIndex == 1);
        STATIC_ASSERT(FCA::kHolderIndex == 0);

        // Set up FunctionCallbackInfo's implicit_args on the stack as follows:
        //
        // Target state:
        //   sp[0 * kPointerSize]: kHolder
        //   sp[1 * kPointerSize]: kIsolate
        //   sp[2 * kPointerSize]: undefined (kReturnValueDefaultValue)
        //   sp[3 * kPointerSize]: undefined (kReturnValue)
        //   sp[4 * kPointerSize]: kData
        //   sp[5 * kPointerSize]: undefined (kNewTarget)

        // Set up the base register for addressing through MemOperands. It will point
        // at the receiver (located at sp + argc * kPointerSize).
        __ Lsa(base, sp, argc, kPointerSizeLog2);

        // Reserve space on the stack.
        __ Subu(sp, sp, Operand(FCA::kArgsLength * kPointerSize));

        // kHolder.
        __ sw(holder, MemOperand(sp, 0 * kPointerSize));

        // kIsolate.
        __ li(scratch, ExternalReference::isolate_address(masm->isolate()));
        __ sw(scratch, MemOperand(sp, 1 * kPointerSize));

        // kReturnValueDefaultValue and kReturnValue.
        __ LoadRoot(scratch, RootIndex::kUndefinedValue);
        __ sw(scratch, MemOperand(sp, 2 * kPointerSize));
        __ sw(scratch, MemOperand(sp, 3 * kPointerSize));

        // kData.
        __ sw(call_data, MemOperand(sp, 4 * kPointerSize));

        // kNewTarget.
        __ sw(scratch, MemOperand(sp, 5 * kPointerSize));

        // Keep a pointer to kHolder (= implicit_args) in a scratch register.
        // We use it below to set up the FunctionCallbackInfo object.
        __ mov(scratch, sp);

        // Allocate the v8::Arguments structure in the arguments' space since
        // it's not controlled by GC.
        static constexpr int kApiStackSpace = 4;
        static constexpr bool kDontSaveDoubles = false;
        FrameScope frame_scope(masm, StackFrame::MANUAL);
        __ EnterExitFrame(kDontSaveDoubles, kApiStackSpace);

        // FunctionCallbackInfo::implicit_args_ (points at kHolder as set up above).
        // Arguments are after the return address (pushed by EnterExitFrame()).
        __ sw(scratch, MemOperand(sp, 1 * kPointerSize));

        // FunctionCallbackInfo::values_ (points at the first varargs argument passed
        // on the stack).
        __ Subu(scratch, base, Operand(1 * kPointerSize));
        __ sw(scratch, MemOperand(sp, 2 * kPointerSize));

        // FunctionCallbackInfo::length_.
        __ sw(argc, MemOperand(sp, 3 * kPointerSize));

        // We also store the number of bytes to drop from the stack after returning
        // from the API function here.
        // Note: Unlike on other architectures, this stores the number of slots to
        // drop, not the number of bytes.
        __ Addu(scratch, argc, Operand(FCA::kArgsLength + 1 /* receiver */));
        __ sw(scratch, MemOperand(sp, 4 * kPointerSize));

        // v8::InvocationCallback's argument.
        DCHECK(!AreAliased(api_function_address, scratch, a0));
        __ Addu(a0, sp, Operand(1 * kPointerSize));

        ExternalReference thunk_ref = ExternalReference::invoke_function_callback();

        // There are two stack slots above the arguments we constructed on the stack.
        // TODO(jgruber): Document what these arguments are.
        static constexpr int kStackSlotsAboveFCA = 2;
        MemOperand return_value_operand(
            fp, (kStackSlotsAboveFCA + FCA::kReturnValueOffset) * kPointerSize);

        static constexpr int kUseStackSpaceOperand = 0;
        MemOperand stack_space_operand(sp, 4 * kPointerSize);

        AllowExternalCallThatCantCauseGC scope(masm);
        CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
            kUseStackSpaceOperand, &stack_space_operand,
            return_value_operand);
    }

    void Builtins::Generate_CallApiGetter(MacroAssembler* masm)
    {
        // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
        // name below the exit frame to make GC aware of them.
        STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
        STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 1);
        STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 2);
        STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 3);
        STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 4);
        STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 5);
        STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 6);
        STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 7);

        Register receiver = ApiGetterDescriptor::ReceiverRegister();
        Register holder = ApiGetterDescriptor::HolderRegister();
        Register callback = ApiGetterDescriptor::CallbackRegister();
        Register scratch = t0;
        DCHECK(!AreAliased(receiver, holder, callback, scratch));

        Register api_function_address = a2;

        // Here and below +1 is for name() pushed after the args_ array.
        typedef PropertyCallbackArguments PCA;
        __ Subu(sp, sp, (PCA::kArgsLength + 1) * kPointerSize);
        __ sw(receiver, MemOperand(sp, (PCA::kThisIndex + 1) * kPointerSize));
        __ lw(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
        __ sw(scratch, MemOperand(sp, (PCA::kDataIndex + 1) * kPointerSize));
        __ LoadRoot(scratch, RootIndex::kUndefinedValue);
        __ sw(scratch, MemOperand(sp, (PCA::kReturnValueOffset + 1) * kPointerSize));
        __ sw(scratch, MemOperand(sp, (PCA::kReturnValueDefaultValueIndex + 1) * kPointerSize));
        __ li(scratch, ExternalReference::isolate_address(masm->isolate()));
        __ sw(scratch, MemOperand(sp, (PCA::kIsolateIndex + 1) * kPointerSize));
        __ sw(holder, MemOperand(sp, (PCA::kHolderIndex + 1) * kPointerSize));
        // should_throw_on_error -> false
        DCHECK_EQ(0, Smi::kZero.ptr());
        __ sw(zero_reg,
            MemOperand(sp, (PCA::kShouldThrowOnErrorIndex + 1) * kPointerSize));
        __ lw(scratch, FieldMemOperand(callback, AccessorInfo::kNameOffset));
        __ sw(scratch, MemOperand(sp, 0 * kPointerSize));

        // v8::PropertyCallbackInfo::args_ array and name handle.
        const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;

        // Load address of v8::PropertyAccessorInfo::args_ array and name handle.
        __ mov(a0, sp); // a0 = Handle<Name>
        __ Addu(a1, a0, Operand(1 * kPointerSize)); // a1 = v8::PCI::args_

        const int kApiStackSpace = 1;
        FrameScope frame_scope(masm, StackFrame::MANUAL);
        __ EnterExitFrame(false, kApiStackSpace);

        // Create v8::PropertyCallbackInfo object on the stack and initialize
        // it's args_ field.
        __ sw(a1, MemOperand(sp, 1 * kPointerSize));
        __ Addu(a1, sp, Operand(1 * kPointerSize)); // a1 = v8::PropertyCallbackInfo&

        ExternalReference thunk_ref = ExternalReference::invoke_accessor_getter_callback();

        __ lw(scratch, FieldMemOperand(callback, AccessorInfo::kJsGetterOffset));
        __ lw(api_function_address,
            FieldMemOperand(scratch, Foreign::kForeignAddressOffset));

        // +3 is to skip prolog, return address and name handle.
        MemOperand return_value_operand(
            fp, (PropertyCallbackArguments::kReturnValueOffset + 3) * kPointerSize);
        MemOperand* const kUseStackSpaceConstant = nullptr;
        CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
            kStackUnwindSpace, kUseStackSpaceConstant,
            return_value_operand);
    }

    void Builtins::Generate_DirectCEntry(MacroAssembler* masm)
    {
        // The sole purpose of DirectCEntry is for movable callers (e.g. any general
        // purpose Code object) to be able to call into C functions that may trigger
        // GC and thus move the caller.
        //
        // DirectCEntry places the return address on the stack (updated by the GC),
        // making the call GC safe. The irregexp backend relies on this.

        // Make place for arguments to fit C calling convention. Callers use
        // EnterExitFrame/LeaveExitFrame so they handle stack restoring and we don't
        // have to do that here. Any caller must drop kCArgsSlotsSize stack space
        // after the call.
        __ Subu(sp, sp, Operand(kCArgsSlotsSize));

        __ sw(ra, MemOperand(sp, kCArgsSlotsSize)); // Store the return address.
        __ Call(t9); // Call the C++ function.
        __ lw(t9, MemOperand(sp, kCArgsSlotsSize)); // Return to calling code.

        if (FLAG_debug_code && FLAG_enable_slow_asserts) {
            // In case of an error the return address may point to a memory area
            // filled with kZapValue by the GC. Dereference the address and check for
            // this.
            __ lw(t0, MemOperand(t9));
            __ Assert(ne, AbortReason::kReceivedInvalidReturnAddress, t0,
                Operand(reinterpret_cast<uint32_t>(kZapValue)));
        }

        __ Jump(t9);
    }

    void Builtins::Generate_MemCopyUint8Uint8(MacroAssembler* masm)
    {
        // This code assumes that cache lines are 32 bytes and if the cache line is
        // larger it will not work correctly.
        {
            Label lastb, unaligned, aligned, chkw, loop16w, chk1w, wordCopy_loop,
                skip_pref, lastbloop, leave, ua_chk16w, ua_loop16w, ua_skip_pref,
                ua_chkw, ua_chk1w, ua_wordCopy_loop, ua_smallCopy, ua_smallCopy_loop;

            // The size of each prefetch.
            uint32_t pref_chunk = 32;
            // The maximum size of a prefetch, it must not be less than pref_chunk.
            // If the real size of a prefetch is greater than max_pref_size and
            // the kPrefHintPrepareForStore hint is used, the code will not work
            // correctly.
            uint32_t max_pref_size = 128;
            DCHECK(pref_chunk < max_pref_size);

            // pref_limit is set based on the fact that we never use an offset
            // greater then 5 on a store pref and that a single pref can
            // never be larger then max_pref_size.
            uint32_t pref_limit = (5 * pref_chunk) + max_pref_size;
            int32_t pref_hint_load = kPrefHintLoadStreamed;
            int32_t pref_hint_store = kPrefHintPrepareForStore;
            uint32_t loadstore_chunk = 4;

            // The initial prefetches may fetch bytes that are before the buffer being
            // copied. Start copies with an offset of 4 so avoid this situation when
            // using kPrefHintPrepareForStore.
            DCHECK(pref_hint_store != kPrefHintPrepareForStore || pref_chunk * 4 >= max_pref_size);

            // If the size is less than 8, go to lastb. Regardless of size,
            // copy dst pointer to v0 for the retuen value.
            __ slti(t2, a2, 2 * loadstore_chunk);
            __ bne(t2, zero_reg, &lastb);
            __ mov(v0, a0); // In delay slot.

            // If src and dst have different alignments, go to unaligned, if they
            // have the same alignment (but are not actually aligned) do a partial
            // load/store to make them aligned. If they are both already aligned
            // we can start copying at aligned.
            __ xor_(t8, a1, a0);
            __ andi(t8, t8, loadstore_chunk - 1); // t8 is a0/a1 word-displacement.
            __ bne(t8, zero_reg, &unaligned);
            __ subu(a3, zero_reg, a0); // In delay slot.

            __ andi(a3, a3, loadstore_chunk - 1); // Copy a3 bytes to align a0/a1.
            __ beq(a3, zero_reg, &aligned); // Already aligned.
            __ subu(a2, a2, a3); // In delay slot. a2 is the remining bytes count.

            if (kArchEndian == kLittle) {
                __ lwr(t8, MemOperand(a1));
                __ addu(a1, a1, a3);
                __ swr(t8, MemOperand(a0));
                __ addu(a0, a0, a3);
            } else {
                __ lwl(t8, MemOperand(a1));
                __ addu(a1, a1, a3);
                __ swl(t8, MemOperand(a0));
                __ addu(a0, a0, a3);
            }
            // Now dst/src are both aligned to (word) aligned addresses. Set a2 to
            // count how many bytes we have to copy after all the 64 byte chunks are
            // copied and a3 to the dst pointer after all the 64 byte chunks have been
            // copied. We will loop, incrementing a0 and a1 until a0 equals a3.
            __ bind(&aligned);
            __ andi(t8, a2, 0x3F);
            __ beq(a2, t8, &chkw); // Less than 64?
            __ subu(a3, a2, t8); // In delay slot.
            __ addu(a3, a0, a3); // Now a3 is the final dst after loop.

            // When in the loop we prefetch with kPrefHintPrepareForStore hint,
            // in this case the a0+x should be past the "t0-32" address. This means:
            // for x=128 the last "safe" a0 address is "t0-160". Alternatively, for
            // x=64 the last "safe" a0 address is "t0-96". In the current version we
            // will use "pref hint, 128(a0)", so "t0-160" is the limit.
            if (pref_hint_store == kPrefHintPrepareForStore) {
                __ addu(t0, a0, a2); // t0 is the "past the end" address.
                __ Subu(t9, t0, pref_limit); // t9 is the "last safe pref" address.
            }

            __ Pref(pref_hint_load, MemOperand(a1, 0 * pref_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 1 * pref_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 2 * pref_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 3 * pref_chunk));

            if (pref_hint_store != kPrefHintPrepareForStore) {
                __ Pref(pref_hint_store, MemOperand(a0, 1 * pref_chunk));
                __ Pref(pref_hint_store, MemOperand(a0, 2 * pref_chunk));
                __ Pref(pref_hint_store, MemOperand(a0, 3 * pref_chunk));
            }
            __ bind(&loop16w);
            __ lw(t0, MemOperand(a1));

            if (pref_hint_store == kPrefHintPrepareForStore) {
                __ sltu(v1, t9, a0); // If a0 > t9, don't use next prefetch.
                __ Branch(USE_DELAY_SLOT, &skip_pref, gt, v1, Operand(zero_reg));
            }
            __ lw(t1, MemOperand(a1, 1, loadstore_chunk)); // Maybe in delay slot.

            __ Pref(pref_hint_store, MemOperand(a0, 4 * pref_chunk));
            __ Pref(pref_hint_store, MemOperand(a0, 5 * pref_chunk));

            __ bind(&skip_pref);
            __ lw(t2, MemOperand(a1, 2, loadstore_chunk));
            __ lw(t3, MemOperand(a1, 3, loadstore_chunk));
            __ lw(t4, MemOperand(a1, 4, loadstore_chunk));
            __ lw(t5, MemOperand(a1, 5, loadstore_chunk));
            __ lw(t6, MemOperand(a1, 6, loadstore_chunk));
            __ lw(t7, MemOperand(a1, 7, loadstore_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 4 * pref_chunk));

            __ sw(t0, MemOperand(a0));
            __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
            __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
            __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
            __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
            __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
            __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
            __ sw(t7, MemOperand(a0, 7, loadstore_chunk));

            __ lw(t0, MemOperand(a1, 8, loadstore_chunk));
            __ lw(t1, MemOperand(a1, 9, loadstore_chunk));
            __ lw(t2, MemOperand(a1, 10, loadstore_chunk));
            __ lw(t3, MemOperand(a1, 11, loadstore_chunk));
            __ lw(t4, MemOperand(a1, 12, loadstore_chunk));
            __ lw(t5, MemOperand(a1, 13, loadstore_chunk));
            __ lw(t6, MemOperand(a1, 14, loadstore_chunk));
            __ lw(t7, MemOperand(a1, 15, loadstore_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 5 * pref_chunk));

            __ sw(t0, MemOperand(a0, 8, loadstore_chunk));
            __ sw(t1, MemOperand(a0, 9, loadstore_chunk));
            __ sw(t2, MemOperand(a0, 10, loadstore_chunk));
            __ sw(t3, MemOperand(a0, 11, loadstore_chunk));
            __ sw(t4, MemOperand(a0, 12, loadstore_chunk));
            __ sw(t5, MemOperand(a0, 13, loadstore_chunk));
            __ sw(t6, MemOperand(a0, 14, loadstore_chunk));
            __ sw(t7, MemOperand(a0, 15, loadstore_chunk));
            __ addiu(a0, a0, 16 * loadstore_chunk);
            __ bne(a0, a3, &loop16w);
            __ addiu(a1, a1, 16 * loadstore_chunk); // In delay slot.
            __ mov(a2, t8);

            // Here we have src and dest word-aligned but less than 64-bytes to go.
            // Check for a 32 bytes chunk and copy if there is one. Otherwise jump
            // down to chk1w to handle the tail end of the copy.
            __ bind(&chkw);
            __ Pref(pref_hint_load, MemOperand(a1, 0 * pref_chunk));
            __ andi(t8, a2, 0x1F);
            __ beq(a2, t8, &chk1w); // Less than 32?
            __ nop(); // In delay slot.
            __ lw(t0, MemOperand(a1));
            __ lw(t1, MemOperand(a1, 1, loadstore_chunk));
            __ lw(t2, MemOperand(a1, 2, loadstore_chunk));
            __ lw(t3, MemOperand(a1, 3, loadstore_chunk));
            __ lw(t4, MemOperand(a1, 4, loadstore_chunk));
            __ lw(t5, MemOperand(a1, 5, loadstore_chunk));
            __ lw(t6, MemOperand(a1, 6, loadstore_chunk));
            __ lw(t7, MemOperand(a1, 7, loadstore_chunk));
            __ addiu(a1, a1, 8 * loadstore_chunk);
            __ sw(t0, MemOperand(a0));
            __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
            __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
            __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
            __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
            __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
            __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
            __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
            __ addiu(a0, a0, 8 * loadstore_chunk);

            // Here we have less than 32 bytes to copy. Set up for a loop to copy
            // one word at a time. Set a2 to count how many bytes we have to copy
            // after all the word chunks are copied and a3 to the dst pointer after
            // all the word chunks have been copied. We will loop, incrementing a0
            // and a1 until a0 equals a3.
            __ bind(&chk1w);
            __ andi(a2, t8, loadstore_chunk - 1);
            __ beq(a2, t8, &lastb);
            __ subu(a3, t8, a2); // In delay slot.
            __ addu(a3, a0, a3);

            __ bind(&wordCopy_loop);
            __ lw(t3, MemOperand(a1));
            __ addiu(a0, a0, loadstore_chunk);
            __ addiu(a1, a1, loadstore_chunk);
            __ bne(a0, a3, &wordCopy_loop);
            __ sw(t3, MemOperand(a0, -1, loadstore_chunk)); // In delay slot.

            __ bind(&lastb);
            __ Branch(&leave, le, a2, Operand(zero_reg));
            __ addu(a3, a0, a2);

            __ bind(&lastbloop);
            __ lb(v1, MemOperand(a1));
            __ addiu(a0, a0, 1);
            __ addiu(a1, a1, 1);
            __ bne(a0, a3, &lastbloop);
            __ sb(v1, MemOperand(a0, -1)); // In delay slot.

            __ bind(&leave);
            __ jr(ra);
            __ nop();

            // Unaligned case. Only the dst gets aligned so we need to do partial
            // loads of the source followed by normal stores to the dst (once we
            // have aligned the destination).
            __ bind(&unaligned);
            __ andi(a3, a3, loadstore_chunk - 1); // Copy a3 bytes to align a0/a1.
            __ beq(a3, zero_reg, &ua_chk16w);
            __ subu(a2, a2, a3); // In delay slot.

            if (kArchEndian == kLittle) {
                __ lwr(v1, MemOperand(a1));
                __ lwl(v1,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
                __ addu(a1, a1, a3);
                __ swr(v1, MemOperand(a0));
                __ addu(a0, a0, a3);
            } else {
                __ lwl(v1, MemOperand(a1));
                __ lwr(v1,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
                __ addu(a1, a1, a3);
                __ swl(v1, MemOperand(a0));
                __ addu(a0, a0, a3);
            }

            // Now the dst (but not the source) is aligned. Set a2 to count how many
            // bytes we have to copy after all the 64 byte chunks are copied and a3 to
            // the dst pointer after all the 64 byte chunks have been copied. We will
            // loop, incrementing a0 and a1 until a0 equals a3.
            __ bind(&ua_chk16w);
            __ andi(t8, a2, 0x3F);
            __ beq(a2, t8, &ua_chkw);
            __ subu(a3, a2, t8); // In delay slot.
            __ addu(a3, a0, a3);

            if (pref_hint_store == kPrefHintPrepareForStore) {
                __ addu(t0, a0, a2);
                __ Subu(t9, t0, pref_limit);
            }

            __ Pref(pref_hint_load, MemOperand(a1, 0 * pref_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 1 * pref_chunk));
            __ Pref(pref_hint_load, MemOperand(a1, 2 * pref_chunk));

            if (pref_hint_store != kPrefHintPrepareForStore) {
                __ Pref(pref_hint_store, MemOperand(a0, 1 * pref_chunk));
                __ Pref(pref_hint_store, MemOperand(a0, 2 * pref_chunk));
                __ Pref(pref_hint_store, MemOperand(a0, 3 * pref_chunk));
            }

            __ bind(&ua_loop16w);
            __ Pref(pref_hint_load, MemOperand(a1, 3 * pref_chunk));
            if (kArchEndian == kLittle) {
                __ lwr(t0, MemOperand(a1));
                __ lwr(t1, MemOperand(a1, 1, loadstore_chunk));
                __ lwr(t2, MemOperand(a1, 2, loadstore_chunk));

                if (pref_hint_store == kPrefHintPrepareForStore) {
                    __ sltu(v1, t9, a0);
                    __ Branch(USE_DELAY_SLOT, &ua_skip_pref, gt, v1, Operand(zero_reg));
                }
                __ lwr(t3, MemOperand(a1, 3, loadstore_chunk)); // Maybe in delay slot.

                __ Pref(pref_hint_store, MemOperand(a0, 4 * pref_chunk));
                __ Pref(pref_hint_store, MemOperand(a0, 5 * pref_chunk));

                __ bind(&ua_skip_pref);
                __ lwr(t4, MemOperand(a1, 4, loadstore_chunk));
                __ lwr(t5, MemOperand(a1, 5, loadstore_chunk));
                __ lwr(t6, MemOperand(a1, 6, loadstore_chunk));
                __ lwr(t7, MemOperand(a1, 7, loadstore_chunk));
                __ lwl(t0,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t1,
                    MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t2,
                    MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t3,
                    MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t4,
                    MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t5,
                    MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t6,
                    MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t7,
                    MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
            } else {
                __ lwl(t0, MemOperand(a1));
                __ lwl(t1, MemOperand(a1, 1, loadstore_chunk));
                __ lwl(t2, MemOperand(a1, 2, loadstore_chunk));

                if (pref_hint_store == kPrefHintPrepareForStore) {
                    __ sltu(v1, t9, a0);
                    __ Branch(USE_DELAY_SLOT, &ua_skip_pref, gt, v1, Operand(zero_reg));
                }
                __ lwl(t3, MemOperand(a1, 3, loadstore_chunk)); // Maybe in delay slot.

                __ Pref(pref_hint_store, MemOperand(a0, 4 * pref_chunk));
                __ Pref(pref_hint_store, MemOperand(a0, 5 * pref_chunk));

                __ bind(&ua_skip_pref);
                __ lwl(t4, MemOperand(a1, 4, loadstore_chunk));
                __ lwl(t5, MemOperand(a1, 5, loadstore_chunk));
                __ lwl(t6, MemOperand(a1, 6, loadstore_chunk));
                __ lwl(t7, MemOperand(a1, 7, loadstore_chunk));
                __ lwr(t0,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t1,
                    MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t2,
                    MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t3,
                    MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t4,
                    MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t5,
                    MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t6,
                    MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t7,
                    MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
            }
            __ Pref(pref_hint_load, MemOperand(a1, 4 * pref_chunk));
            __ sw(t0, MemOperand(a0));
            __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
            __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
            __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
            __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
            __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
            __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
            __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
            if (kArchEndian == kLittle) {
                __ lwr(t0, MemOperand(a1, 8, loadstore_chunk));
                __ lwr(t1, MemOperand(a1, 9, loadstore_chunk));
                __ lwr(t2, MemOperand(a1, 10, loadstore_chunk));
                __ lwr(t3, MemOperand(a1, 11, loadstore_chunk));
                __ lwr(t4, MemOperand(a1, 12, loadstore_chunk));
                __ lwr(t5, MemOperand(a1, 13, loadstore_chunk));
                __ lwr(t6, MemOperand(a1, 14, loadstore_chunk));
                __ lwr(t7, MemOperand(a1, 15, loadstore_chunk));
                __ lwl(t0,
                    MemOperand(a1, 9, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t1,
                    MemOperand(a1, 10, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t2,
                    MemOperand(a1, 11, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t3,
                    MemOperand(a1, 12, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t4,
                    MemOperand(a1, 13, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t5,
                    MemOperand(a1, 14, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t6,
                    MemOperand(a1, 15, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t7,
                    MemOperand(a1, 16, loadstore_chunk, MemOperand::offset_minus_one));
            } else {
                __ lwl(t0, MemOperand(a1, 8, loadstore_chunk));
                __ lwl(t1, MemOperand(a1, 9, loadstore_chunk));
                __ lwl(t2, MemOperand(a1, 10, loadstore_chunk));
                __ lwl(t3, MemOperand(a1, 11, loadstore_chunk));
                __ lwl(t4, MemOperand(a1, 12, loadstore_chunk));
                __ lwl(t5, MemOperand(a1, 13, loadstore_chunk));
                __ lwl(t6, MemOperand(a1, 14, loadstore_chunk));
                __ lwl(t7, MemOperand(a1, 15, loadstore_chunk));
                __ lwr(t0,
                    MemOperand(a1, 9, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t1,
                    MemOperand(a1, 10, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t2,
                    MemOperand(a1, 11, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t3,
                    MemOperand(a1, 12, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t4,
                    MemOperand(a1, 13, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t5,
                    MemOperand(a1, 14, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t6,
                    MemOperand(a1, 15, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t7,
                    MemOperand(a1, 16, loadstore_chunk, MemOperand::offset_minus_one));
            }
            __ Pref(pref_hint_load, MemOperand(a1, 5 * pref_chunk));
            __ sw(t0, MemOperand(a0, 8, loadstore_chunk));
            __ sw(t1, MemOperand(a0, 9, loadstore_chunk));
            __ sw(t2, MemOperand(a0, 10, loadstore_chunk));
            __ sw(t3, MemOperand(a0, 11, loadstore_chunk));
            __ sw(t4, MemOperand(a0, 12, loadstore_chunk));
            __ sw(t5, MemOperand(a0, 13, loadstore_chunk));
            __ sw(t6, MemOperand(a0, 14, loadstore_chunk));
            __ sw(t7, MemOperand(a0, 15, loadstore_chunk));
            __ addiu(a0, a0, 16 * loadstore_chunk);
            __ bne(a0, a3, &ua_loop16w);
            __ addiu(a1, a1, 16 * loadstore_chunk); // In delay slot.
            __ mov(a2, t8);

            // Here less than 64-bytes. Check for
            // a 32 byte chunk and copy if there is one. Otherwise jump down to
            // ua_chk1w to handle the tail end of the copy.
            __ bind(&ua_chkw);
            __ Pref(pref_hint_load, MemOperand(a1));
            __ andi(t8, a2, 0x1F);

            __ beq(a2, t8, &ua_chk1w);
            __ nop(); // In delay slot.
            if (kArchEndian == kLittle) {
                __ lwr(t0, MemOperand(a1));
                __ lwr(t1, MemOperand(a1, 1, loadstore_chunk));
                __ lwr(t2, MemOperand(a1, 2, loadstore_chunk));
                __ lwr(t3, MemOperand(a1, 3, loadstore_chunk));
                __ lwr(t4, MemOperand(a1, 4, loadstore_chunk));
                __ lwr(t5, MemOperand(a1, 5, loadstore_chunk));
                __ lwr(t6, MemOperand(a1, 6, loadstore_chunk));
                __ lwr(t7, MemOperand(a1, 7, loadstore_chunk));
                __ lwl(t0,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t1,
                    MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t2,
                    MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t3,
                    MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t4,
                    MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t5,
                    MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t6,
                    MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwl(t7,
                    MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
            } else {
                __ lwl(t0, MemOperand(a1));
                __ lwl(t1, MemOperand(a1, 1, loadstore_chunk));
                __ lwl(t2, MemOperand(a1, 2, loadstore_chunk));
                __ lwl(t3, MemOperand(a1, 3, loadstore_chunk));
                __ lwl(t4, MemOperand(a1, 4, loadstore_chunk));
                __ lwl(t5, MemOperand(a1, 5, loadstore_chunk));
                __ lwl(t6, MemOperand(a1, 6, loadstore_chunk));
                __ lwl(t7, MemOperand(a1, 7, loadstore_chunk));
                __ lwr(t0,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t1,
                    MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t2,
                    MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t3,
                    MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t4,
                    MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t5,
                    MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t6,
                    MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
                __ lwr(t7,
                    MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
            }
            __ addiu(a1, a1, 8 * loadstore_chunk);
            __ sw(t0, MemOperand(a0));
            __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
            __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
            __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
            __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
            __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
            __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
            __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
            __ addiu(a0, a0, 8 * loadstore_chunk);

            // Less than 32 bytes to copy. Set up for a loop to
            // copy one word at a time.
            __ bind(&ua_chk1w);
            __ andi(a2, t8, loadstore_chunk - 1);
            __ beq(a2, t8, &ua_smallCopy);
            __ subu(a3, t8, a2); // In delay slot.
            __ addu(a3, a0, a3);

            __ bind(&ua_wordCopy_loop);
            if (kArchEndian == kLittle) {
                __ lwr(v1, MemOperand(a1));
                __ lwl(v1,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
            } else {
                __ lwl(v1, MemOperand(a1));
                __ lwr(v1,
                    MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
            }
            __ addiu(a0, a0, loadstore_chunk);
            __ addiu(a1, a1, loadstore_chunk);
            __ bne(a0, a3, &ua_wordCopy_loop);
            __ sw(v1, MemOperand(a0, -1, loadstore_chunk)); // In delay slot.

            // Copy the last 8 bytes.
            __ bind(&ua_smallCopy);
            __ beq(a2, zero_reg, &leave);
            __ addu(a3, a0, a2); // In delay slot.

            __ bind(&ua_smallCopy_loop);
            __ lb(v1, MemOperand(a1));
            __ addiu(a0, a0, 1);
            __ addiu(a1, a1, 1);
            __ bne(a0, a3, &ua_smallCopy_loop);
            __ sb(v1, MemOperand(a0, -1)); // In delay slot.

            __ jr(ra);
            __ nop();
        }
    }

#undef __

} // namespace internal
} // namespace v8

#endif // V8_TARGET_ARCH_MIPS
